JP2001052926A - Inductance element, electron gun, and cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an inductance element which operates in a vacuum and in an environment where a high-voltage is applied in a cathode tube and so on. SOLUTION: For example, on both surfaces of a rectangular insulating substrate 11, which is composed of a ceramic substrate and so on having a through hole 13 substantially at the center, inductance circuits 12-1 and 12-2 are formed to configure a plate-like inductance element 10. The inductance circuits 12-1 and 12-2 are formed each by patterning an electrical conductor into a rectangular spiral and the like around the through hole 13 serving as the center. Further, an electrical conductor 14 is applied to the wall surface of the through hole 13. Terminals 12-1A and 12-2A of the respective inductance circuits 12-1 and 12-2 are electrically connected to each other through the electrical conductor 14. The other terminals 12-1B and 12-2B serve as terminals of the inductance element 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductance element, an electron gun equipped with the inductance element, and a cathode ray tube incorporating the electron gun.

[0002]

2. Description of the Related Art In an electron gun, an AC voltage synchronized with deflection of an electron beam is applied to a first focus electrode, while a constant voltage is applied to a second focus electrode in order to make the shape of the electron beam uniform over the entire screen. Is applied. As described above, in order to apply a voltage different from that of the first focus electrode to the second focus electrode, generally, a dedicated DC power supply is prepared outside the cathode ray tube incorporating the electron gun, and the DC power from the DC power supply is generally used. A DC voltage is supplied to the inside of the cathode ray tube through a lead wire. Therefore, the cost of the product is increased by the provision of the external power supply.

For this reason, conventionally, a constant DC voltage is extracted by passing an AC voltage applied to a first focus electrode through a low-frequency component transmission function circuit (low-pass filter) mounted on an electron gun. Attempts have been made to reduce the cost of products by eliminating the need for an external power supply by using it as a DC voltage applied to the electrodes.

As the low-frequency component transmission function circuit, a circuit having a circuit configuration including a combination of a capacitance element and an inductance element is generally used. here,
As an inductance element, an element obtained by simply winding a single metal wire into a coil shape is generally known.

However, regarding the inductance element,
Considering the use in a vacuum, the heat resistance at high heat (about 400 degrees) when producing the vacuum tube, and the gas release during the long-term use,
Insulation treatment with organic resin is difficult. However, in the case of a mere bare wire coil, it is inevitable that metal dust adheres to the coil wire, and a projection due to a scratch or the like occurs in the manufacturing process. These defects cause discharge and lightning in a cathode ray tube when a high voltage of about 30 kV is applied in a working state after completion.

[0006] For the above-described reason, an inductance element cannot be used in a low-frequency component transmission function circuit used in a cathode ray tube. Therefore, a pseudo low-frequency component transmission function circuit is configured by using a resistance element instead of an inductance element. That is the current situation.

[0007]

That is, in the case of a pseudo low frequency component transmission function circuit constituted by using a resistance element instead of an inductance element, since the circuit has no inductance component, it is constituted by using an inductance element. Transmission characteristics of low frequency components such as circuits (smoothing characteristics)
Is not obtained, the DC voltage after transmission includes a pulsating flow.

If the DC voltage including the pulsating current is applied to the second focus electrode, the intended purpose of making the spot shape of the electron beam uniform over the entire screen cannot be sufficiently achieved. For these reasons, in the technical field of electron guns and cathode ray tubes, there is a strong demand for inductance elements that can be used even in vacuum. Also,
Such an element can be applied not only to application as a simple circuit element but also to operation of an electron beam in a vacuum more closely by a generated magnetic field.

The present invention has been made in view of the above problems, and has as its object to provide an inductance element which can be used in a vacuum and can be used for applications other than circuit elements. And a cathode ray tube incorporating the electron gun.

[0010]

The inductance element according to the present invention has an inductance circuit formed spirally around the through hole on both sides of the insulating substrate having the through hole, and each of the inductance circuits on each surface is provided. Are electrically connected to each other through a through hole.
And the inductance circuit is covered with an insulating film.

An electron gun according to the present invention is provided with an inductance element having the above-described configuration, and for example, a low-frequency component transmission function circuit for extracting a DC component of an AC voltage synchronized with the deflection of an electron beam using the inductance element. Or an electromagnetic focusing element for focusing an electron beam emitted from the cathode electrode.

In the cathode ray tube according to the present invention, the inductance element having the above-described structure is built in the picture tube together with the electron gun. Constitutes a deflection element for deflecting the electron beam emitted from the electron gun.

In the inductance element having the above configuration, an electron gun equipped with the inductance element, and a cathode ray tube incorporating the same,
When the inductance element is constituted by an inductance circuit formed on an insulating substrate, the element becomes a plate-shaped element. Therefore, it can be applied to various uses other than the use in the case of the coil shape.

In particular, since the inductance circuit is covered with an insulating film, insulation can be maintained, gas can be released from the circuit pattern, and long-term deterioration of the pattern can be prevented.
It can be used in a vacuum. In addition, since one end of each of the inductance circuits on each surface is electrically connected through the through-hole by the conductive portion, it is not necessary to connect them using a jumper wire.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1A and 1B are configuration diagrams showing an inductance element according to an embodiment of the present invention, wherein FIG. 1A is a surface view, FIG. 1B is a side view, and FIG.
Respectively shows the rear view.

The inductance element 10 according to the present embodiment
Is composed of, for example, a rectangular insulating substrate 11 made of a ceramic substrate or the like, and inductance circuits 12-1 and 12-2 in which electric conductors are formed on both surfaces of the insulating substrate 11 in a rectangular spiral shape, for example. Configuration. The inductance circuits 12-1 and 12-2 are formed in reverse winding patterns. A through hole 13 is formed substantially at the center of the insulating substrate 11, and an electric conductor 14 is applied to a wall surface of the through hole 13.

The electric conductor 14 is connected to one end 12-1 of each of the inductance circuits 12-1 and 12-2 on both sides.
A and 12-2A constitute a conductive portion for electrically connecting them. The other ends 12-1B and 12-2B of the inductance circuits 12-1 and 12-2 are connected to the inductance element 1-1.
0 at both ends. In the case of application in a vacuum, the inductance circuits 12-1 and 12-2 are covered with an insulating film (not shown) such as a glass film.

Since the inductance element 10 configured as described above has a plate-like shape, it can be used not only for the conventional coil-shaped inductance element but also for an electromagnetic focusing element and a deflection element. Various applications are conceivable. The specific application (application example) will be described later in detail. In particular, the inductance circuit 1
Since 2-1 and 12-2 are covered with an insulating film,
Since insulation retention, gas emission from the circuit pattern, and long-term deterioration of the pattern can be prevented, use in a vacuum is possible.

In addition, the inductance circuits 12-1 and 12-2 formed on both surfaces of the insulating substrate 11 have one ends 1 thereof.
2-1A and 12-2A pass through the through hole 13 and the electric conductor 14
Are electrically connected to each other, so that each end 12-1
The inductance element 10 can be configured without connecting A, 12-2A using a jumper wire (conductor). It is not preferable that the connection is made by using a jumper wire because a magnetic field formed when a current flows through the inductance element 10 is disturbed.

It is to be noted that a plurality of the present inductance elements 10 are stacked, and the end 12-2B of the inductance circuit 12-2 on the back side of the upper inductance element and the inductance circuit 12-1 on the front side of the lower inductance element are formed. It is also possible to adopt a configuration in which the end 12-1B is sequentially connected for each layer. According to this, the inductance circuit 12
Since the number of turns of the pattern (electric conductor) forming -1, 12-2 increases, the intensity of the generated magnetic field can be increased. This technology uses the inductance circuits 12-1 and 12-1.
-2 It can be applied to both the element covered with the insulating film and the element not covered.

Here, the inductance element 1 having the above configuration
A specific method of creating 0 will be described. First, for example, an alumina ceramic substrate (11) having a through-hole (13) formed therein is sintered, and a circuit pattern made of an electric conductor is printed on the surface of the substrate by a known thick-film printing technique. 1, 12-2) are formed. Next, a coating process is performed with, for example, a glass paste, and firing is performed.

In the above-described embodiment, the rectangular spirally wound inductance circuits 12-1 and 12-2 are formed on the rectangular insulating substrate 11, but the insulating substrate 11 and the inductance circuit 12-1 are patterned. , 12-2 may have any shape, for example, a pattern in which an inductance circuit is formed in a circular spiral on a circular insulating substrate, or a circular spiral on a rectangular insulating substrate. An embodiment in which an inductance circuit is formed in a pattern can be considered.

In the above embodiment, the case where the alumina ceramic substrate is used as the insulating substrate 11 has been described as an example. However, the present invention is not limited to this, and a magnetic substrate whose surface is insulated, preferably a strong substrate is used. It is also possible to use a magnetic substrate, specifically, a ferrite substrate that has been subjected to a ceramic coating treatment. According to this, the generated magnetic flux can be concentrated.

Further, depending on the use of the present inductance element 10, there are cases where the magnetic field generated by the element 10 does not affect the surrounding magnetic field, or conversely, the element 10 must not be affected by the surrounding magnetic field. is there. In such a case, at least the periphery of the inductance circuits 12-1 and 12-2 may be covered with a magnetic material such as ferrite and magnetically shielded.

Next, the use of the inductance element 10 according to the above embodiment, that is, an application example will be described.

First, as a first application example, a case where a low-frequency component transmission function circuit (low-pass filter) is formed using the inductance element 10 and mounted on an electron gun will be described as an example. Since the electron gun is used by being built in a cathode ray tube, that is, used in a vacuum, in the case of this application example, the electron gun is mounted on the inductance circuits 12-1 and 12-2 in FIG. Is covered with an insulating film.

When used by mounting on an electron gun,
The magnetic field generated by the inductance element 10 affects the magnetic field in the cathode ray tube, or conversely, the inductance element 1
0 must not be affected by the surrounding magnetic field. Therefore, in use, as shown in FIG. 2, the present inductance element 10 is used by being housed in a magnetic shield case 15 made of a ferromagnetic material. Further, by embedding the ferromagnetic material 16 in the through hole 13 of the insulating substrate 11,
Configure a magnetic circuit.

As shown in FIG. 3, the inductance element 10 constitutes a low-frequency component transmission function circuit 17 with stray capacitances C1 and C2 parasitic at both ends. The low-frequency component transmission function circuit 17 generates a periodically fluctuating voltage applied to a certain electric field focusing electrode (focus electrode) in the multi-stage electric field focusing electron gun, that is, an AC voltage synchronized with the deflection of the electron beam (for example, Parabolic voltage)
It functions to generate a voltage that does not fluctuate periodically, that is, a constant DC voltage.

FIG. 4 shows a mounting example in which the inductance element 10 constituting the low frequency component transmission function circuit 17 is mounted on a multi-stage electric field focusing electron gun. Since the inductance element 10 according to the present embodiment can be used in a vacuum as described above, it can be mounted on an electron gun and incorporated in a cathode ray tube.

In FIG. 4, a multi-stage electric field focusing electron gun 20
Are the first grid electrode 21, the second grid electrode 22, the third grid electrode electrode 23, the fourth grid electrode 24,
A grid electrode 25, a sixth grid electrode 26, and a seventh grid electrode 27;
7 is supported by a pair of bead glasses 28A and 28B which are insulators.

In the multistage electric field focusing electron gun 20 having the above-described configuration, a quadrupole electron lens is formed by the third grid electrode 23, the fourth grid electrode 24, and the fifth grid electrode 25, and the fifth grid electrode 25, the sixth grid Electrode 26
A focus lens (main electron lens) is constituted by the seventh grid electrode 27. Further, the third grid electrode 23 and the fifth grid electrode 25 serve as a first focus electrode, and the fourth grid electrode 24 serves as a second focus electrode.

The first focus electrodes (23, 25) have
An AC voltage (focus voltage) of a parabolic wave synchronized with the deflection of the electron beam is applied. This is a voltage required to make the convergence on the screen uniform since the distance between the electron gun and the screen changes depending on the deflection angle of the electron beam. A certain DC voltage is applied to the second focus electrode (24). This is because the spot shape on the screen of the electron beam changes due to the opening shape of each electrode and the potential difference.
This voltage is required to make the spot shape of the electron beam uniform over the entire screen.

In this application example, as shown in FIG. 4, the low frequency component transmission function circuit 17 is formed by mounting the inductance element 10 according to the present embodiment on the multistage electric field focusing electron gun 20, as shown in FIG. The DC voltage is generated by smoothing the AC voltage applied to the first focus electrodes (23, 25) in the frequency component transmitting function circuit 17 in the low frequency component transmitting function circuit 17, and this DC voltage is converted to the second voltage. The voltage is applied to the focus electrode (24).

As described above, the low-frequency component transmitting function circuit 1 using the inductance element 10 mounted on the electron gun 20 is used.
7, and a constant DC voltage applied to the second focus electrode (24) is generated by the electron gun 20 itself by using the low frequency component transmission function circuit 17, so that it is dedicated to the outside of the cathode ray tube. It is no longer necessary to provide a DC power supply and to take a DC voltage into the cathode ray tube through the lead wire.

In particular, since the low-frequency component transmission function circuit 17 is configured by using the inductance element 10, compared with the conventional configuration in which the low-frequency component transmission function circuit is configured by using a resistance element, as compared with the conventional case. It is possible to obtain better transmission characteristics (smoothing characteristics) of low frequency components. Therefore, since the AC voltage can be reliably smoothed, a DC voltage that does not include a pulsating flow can be applied to the second focus electrode (24). As a result, the spot shape of the electron beam can be reliably made uniform over the entire screen.

In this application example, the low-frequency component transmission function circuit 17 is configured by using the inductance element 10,
It is said that it is mounted on the electron gun 20 and built in the cathode ray tube,
In addition to such uses, a use in which the inductance element 10 is built in a vacuum tube as a choke element is also conceivable.

FIG. 5 is a schematic perspective view showing an overall image of a cathode ray tube incorporating a multi-stage electric field focusing electron gun 20 according to the first application example. In FIG. 5, a panel 32 having an inner surface provided with a fluorescent screen is attached to the opening of the picture tube valve 31, and an electron gun 33 for emitting an electron beam is sealed at the rear end of the picture tube valve 31. . As the electron gun 33, the multi-stage electric field focusing electron gun 20 according to the first application example is used. A cone-shaped deflection yoke 34 for deflecting the electron beam emitted from the electron gun 33 is attached to the neck of the picture tube 31.

In the first application example described above, the case where the inductance element 10 is used as a circuit element constituting the low-frequency component transmission function circuit 17 in the multi-stage electric field focusing electron gun 20 has been described as an example, but is emitted from the cathode electrode. It can also be used as an electromagnetic focusing element for focusing an electron beam. This will be described below as a second application example.

As shown in FIGS. 6A to 6C, an inductance element 10 'according to the second application example is formed of a circular insulating substrate 41 having a large-diameter conductive hole 43 at a substantially central portion. On both sides, inductance circuits 42-1 and 42-2 are formed in a spiral shape, and the inductance circuits 42-1 and 42-2 are passed through an electric conductor 44 applied to the inner wall of the conduction hole 43.
Are electrically connected to one end portions 42-1A and 42-2A.

In the donut-shaped inductance element 10 'having the above structure, both ends 42-1B and 42-2B are provided.
When a current in a certain direction flows between them, a magnetic field in a rotational direction corresponding to the direction of the current is generated around the ring. Note that a stronger magnetic field can be generated by fitting a ring-shaped ferromagnetic material into the through-hole 43.

As shown in FIG. 7, two inductance elements 10 '(10'A) are provided in the multi-stage electric field focusing electron gun 20 so that the center of the through-hole 43 coincides with the center axis O of the electron beam. , 10'B). Then, a current is caused to flow through these inductance elements 10'A and 10'B so that a reverse magnetic field is generated around the ring.

As described above, the two inductance elements 1
0'A and 10'B are arranged face-to-face, and a counter-rotating magnetic field is generated around each ring of these elements 10'A and 10'B, whereby two inductance elements 1
A magnetic lens is formed between 0'A and 10'B. This magnetic lens functions to converge the electron beam passing through the through hole 43. That is, the two inductance elements 10'A and 10'B function as electromagnetic focusing elements for focusing the electron beam.

As described above, by mounting the two inductance elements 10'A and 10'B on the multi-stage electric field focusing electron gun 20 as electromagnetic focusing elements, a magnetic field for converging the electron beam is generated closer to the beam. Therefore, the electron beam can be converged with less power consumption. Further, the magnetic field convergence is more advantageous for a high voltage acceleration electron gun because the convergence of magnetic field convergence increases as the speed of the electron beam increases, as compared with electric field convergence.

In this application example, the case where the inductance elements 10'A and 10'B are used as an electromagnetic focusing element for focusing an electron beam has been described as an example. It is equally applicable.

Next, a third application example of the present invention will be described. In the third application example, a case where the inductance element 10 according to the present embodiment is used in a cathode ray tube as a deflection element for deflecting an electron beam emitted from an electron gun, instead of a conventional deflection coil.

FIG. 8 is an operation schematic diagram for explaining the operation principle when the inductance element 10 is used as a deflection element. In FIG. 8, two inductance elements 10A and 10B are arranged facing each other up and down with the electron beam path therebetween, and these elements 10A and 10B are connected in series so that a current flows between both ends. Then
A magnetic field perpendicular to the surfaces of the inductance elements 10A and 10B is generated in a direction corresponding to the direction of the current.

As a result, in a plane perpendicular to the magnetic field, a force having a magnitude and direction corresponding to the magnitude and direction of the current acts on the electron beam. Therefore, the electron beam can be deflected in the horizontal direction (left and right directions of the screen) by passing a sawtooth current to the inductance elements 10A and 10B. According to the same operation principle, the two inductance elements 10A and 10B are disposed to face each other across the path of the electron beam, and a current of a saw-tooth wave is caused to deflect the electron beam in the vertical direction (vertical direction of the screen). Can be done.

FIG. 9 is a schematic perspective view showing an overall image of a cathode ray tube according to a third application example using the inductance element 10 as a deflection element. In FIG. 9, the picture tube valve 51
A panel 52 having a fluorescent screen provided on the inner surface is mounted in the opening of the image display device, and an electron gun 53 for emitting an electron beam is sealed in the rear end of the picture tube 51. A deflection element 54 for deflecting the electron beam emitted from the electron gun 53 is provided inside the neck portion of the picture tube 51.

The deflecting element 54 includes a pair of inductance elements 10A and 10B which are vertically arranged with the path of the electron beam therebetween so as to deflect the electron beam emitted from the electron gun 53 in the horizontal direction of the screen. A pair of inductance elements 10 disposed on the left and right sides of the path of the electron beam so as to deflect the electron beam in the vertical direction of the screen.
C and 10D. A pair of inductance elements 10A and 10B is supplied with a horizontal deflection current of a sawtooth wave from a horizontal deflection circuit (not shown), and a pair of inductance elements 10C and 10D is a vertical deflection circuit of a sawtooth wave from a vertical deflection circuit (not shown). A deflection current is supplied.

As described above, two sets of inductance elements 10A and 10B and inductance elements 10C and 10D
And the deflecting element 54 and the picture tube valve 51
Built-in, and deflects the electron beam emitted from the electron gun 53 by the generated magnetic field, as compared with the conventional case in which the magnetic field is deflected by a deflection coil disposed outside the picture tube valve 51. Since the magnetic field can be generated closer to the electron beam, the electron beam can be efficiently deflected with less power consumption.

In this application example, two sets of inductance elements 10A and 10B and inductance elements 10C and 1C are used.
Although the case where 0D is used as a deflecting element for deflecting an electron beam has been described as an example, the present invention is not limited to the electron beam, and is similarly applicable to charged particles.

[0052]

As described above, according to the present invention,
Inductance elements, electron guns equipped with the same, and cathode ray tubes incorporating the same, the inductance element is formed by an inductance circuit formed on an insulating substrate, and is a plate-shaped element. It can be applied to various applications, especially by covering the inductance circuit with an insulating film.
Since insulation retention, gas emission from the circuit pattern, and long-term deterioration of the pattern can be prevented, use in a vacuum is possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an inductance element according to an embodiment of the present invention, wherein (A) is a front view, (B) is a side view, and (C) is a back view.

FIG. 2 is a cross-sectional view illustrating a configuration example of a usage form in a first application example.

FIG. 3 is an equivalent circuit diagram of a low-frequency component transmission function circuit configured using an inductance element.

FIG. 4 is a schematic configuration diagram showing a mounting example when an inductance element is mounted on a multi-stage electric field focusing electron gun.

FIG. 5 is a schematic perspective view showing an overall image of a cathode ray tube incorporating a multi-stage electric field focusing electron gun according to a first application example.

6A and 6B are configuration diagrams illustrating an inductance element according to a second application example, wherein FIG. 6A is a front view, FIG. 6B is a side view, and FIG. 6C is a rear view.

FIG. 7 is a schematic diagram illustrating an operation principle of an electromagnetic focusing element according to a second application example.

FIG. 8 is a schematic diagram illustrating an operation principle of a deflection element according to a third application example.

FIG. 9 is a schematic perspective view showing an overall image of a cathode ray tube incorporating a deflection element according to a third application example.

[Explanation of symbols]

10, 10A, 10B, 10C, 10D, 10 ', 1
0'A, 10'B ... inductance elements, 11, 41 ...
Insulating substrate, 12-1, 12-2, 41-1, 42-2: inductance circuit, 13, 43: through hole, 14, 44: electric conductor (conductive portion), 15: magnetic shield case, 17: low Frequency component transmission function circuit (low-pass filter), 20 ...
Multi-stage electric field focusing electron gun

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // H01F 27/28 H01F 15/02 K

Claims (15)

[Claims] 1. An insulating substrate having a through hole, an inductance circuit formed spirally around the through hole on both surfaces of the insulating substrate, and each of the inductance circuits formed on both surfaces of the insulating substrate. And a conducting part for electrically connecting one end through the through hole. 2. The inductance element according to claim 1, further comprising an insulating coating covering the inductance circuit. 3. The inductance element according to claim 1, wherein a plurality of the insulating substrates on which the inductance circuits are formed are stacked, and ends of the inductance circuits of the respective insulating substrates are sequentially connected. 4. The inductance element according to claim 2, wherein a plurality of the insulating substrates on which the inductance circuits are formed are stacked, and ends of the inductance circuits of the respective insulating substrates are sequentially connected. 5. The inductance element according to claim 1, wherein said insulating substrate is a ceramic substrate. 6. The inductance element according to claim 1, wherein the insulating substrate is a magnetic substrate whose surface is insulated. 7. The inductance element according to claim 1, wherein an insulated magnetic body is provided in the through hole. 8. The inductance element according to claim 1, wherein the insulating substrate on which the inductance circuit is formed is housed in a magnetic shield case. 9. An insulated substrate is formed spirally around the through hole on both sides of the insulating substrate having the through hole, and one end of each of the inductance circuits on each surface is electrically connected through the through hole. An electron gun having an inductance element having the inductance circuit covered with an insulating film. 10. A low-frequency component transmission function circuit using the inductance element, wherein an AC voltage synchronized with electron beam deflection is applied to a first focus electrode, and the AC voltage is transmitted to the low-frequency component. The electron gun according to claim 9, wherein a DC voltage obtained through the function circuit is applied to each of the second focus electrodes. 11. The electron gun according to claim 9, wherein said inductance element forms an electromagnetic focusing element for focusing an electron beam emitted from a cathode electrode. 12. An insulated substrate is formed spirally around both sides of an insulating substrate having a through hole, and one end of each of the inductance circuits on each surface is electrically connected through the through hole. A cathode ray tube, wherein an inductance element having the inductance circuit covered with an insulating film is built in a picture tube bulb together with an electron gun. 13. The electron gun has a low-frequency component transmission function circuit configured by using the inductance element. An AC voltage synchronized with the deflection of the electron beam is applied to a first focus electrode, and the AC voltage is applied to the first focus electrode. 13. The cathode ray tube according to claim 12, wherein a DC voltage obtained through the low frequency component transmission function circuit is applied to each of the second focus electrodes. 14. The cathode ray tube according to claim 12, wherein said inductance element forms an electromagnetic focusing element for focusing an electron beam emitted from a cathode electrode in said electron gun. 15. The cathode ray tube according to claim 12, wherein the inductance element constitutes a deflection element for deflecting an electron beam emitted from the electron gun in the picture tube valve.