JPH0718429U - Flyback transformer - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the high-voltage resistor built into the flyback transformer from being affected by ringing components from the secondary coil and switch noise, and also to reduce the size of the flyback transformer. [Structure] A concave portion 29 is formed on an alumina substrate 19, a high voltage resistor 9 is formed by printing on a concave surface 20 of the concave portion 29, and terminals 17, 21, 22 of the high voltage resistor 9 are formed on groove portions 27, 25 of the alumina substrate 19, respectively. Take out from 26. The printed surface of the high voltage resistor 9 is covered with an alumina cover plate 28.
Then, the alumina lid plate 28 is bonded and fixed to the alumina substrate 19. A shield conductive band 30 is formed of copper or the like on the periphery of this adhesively fixed product, and a ground terminal 31 drawn out from the shield conductive band 30 is connected to the ground side. Since the ringing component and the switch noise are absorbed by the shield conductive band 30, the high voltage resistor 9 is not affected by the ringing component or the like.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a flyback transformer mounted on a television receiver or a display device.

[0002]

[Prior art]

 FIG. 8 shows a circuit configuration of a flyback transformer mounted on a television receiver or a display device. The flyback transformer 1 includes a primary coil 2 and a secondary coil 3 having a plurality of rectifying diodes 17 interposed between laminated coils 18, boosts a flyback pulse applied from the primary coil 2, The high voltage output voltage is applied to the anode of the cathode ray tube 6 via a half-wave rectifying circuit composed of a high voltage rectifying diode 4 and a smoothing capacitor 5. Further, the high-voltage output voltage applied to the anode of the cathode ray tube 6 is divided by the high-voltage resistor 9 composed of the voltage-dividing resistors 7 and 8 and taken out. It is fed back to the horizontal output circuit so that

The high-voltage resistor 9 has an element shape as shown in FIG. 7, and is formed by printing a conductive resistance material in a wavy pattern on the surface of the alumina substrate 16. By providing the voltage dividing terminal 24 at the desired position, the voltage dividing resistors 7 and 8 are formed.

A mounting configuration of a flyback transformer having the high-voltage resistor 9 built therein is shown in FIG. The circuit 37 of the flyback transformer 1 surrounded by the chain line in FIG. 8 is housed in a transformer case (not shown), and the aluminum substrate 16 on which the high-voltage resistor 9 is formed by printing is mounted on the holder 15. Then, the claws 35 formed on the back surface of the holder 15 are engaged with the engaging portions (not shown) of the coil assembly 36 of the primary coil 2 and the secondary coil 3, whereby the alumina substrate 16 Are detachably attached to the coil assembly 36.

[0005]

[Problems to be solved by the device]

 However, as described above, when the high-voltage resistor 9 is built in the flyback transformer, the high-voltage resistor 9 is exposed and printed on the surface of the alumina substrate 16, so that the secondary coil 3 side is exposed. The high-frequency resistor 9 receives the ringing component of the generated harmonics, the switch noise caused by the switch operation when the rectifying diode 17 provided in the secondary coil 3 is turned on and off when the flyback transformer 1 is operated, and the like. There were problems such as easy riding, poor response of the correction performance in the high-voltage correction circuit, and a striping pattern of the ringing component on the screen. To alleviate such a problem, it may be possible to dispose the secondary coil 3 and the high-voltage resistor 9 at positions as far apart as possible, but in order to reduce the size of the flyback transformer, both of them should be used. There was a limit to how large the distance between 3 and 9 could be, and it was not an effective solution.

It is also conceivable that the high voltage resistor 9 is covered with a metal shield member so that the high voltage resistor 9 is not affected by the ringing component and the switch noise as described above. Since the conductive resistance material of the high-voltage resistor 9 exposed and printed on the surface and the metal shield member are short-circuited, even in this case, it was not a solution to the above problem.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to prevent a ringing component and a switch noise from riding on a high voltage resistor, thereby providing a high voltage correction circuit. The objective is to provide a small flyback transformer with a built-in high-voltage resistor that improves the responsiveness of the correction performance and provides a clear image.

[0008]

[Means for Solving the Problems]

 The present invention is configured as follows to achieve the above object. That is, the present invention is a flyback transformer having a built-in high-voltage resistor for detecting a high-voltage output voltage output from a secondary coil to a cathode ray tube, the high-voltage resistor being printed on the surface of an insulating substrate. The insulating substrate is covered with an insulating cover plate covering the printed surface of the high-voltage resistor, and a shield conductive band is formed around the insulating substrate and the insulating cover plate to cover the high-voltage resistor. It is characterized by being present.

[0009]

[Action]

 The insulating substrate on which the high-voltage resistor is printed is covered with an insulating cover plate covering the printed surface, and the outer periphery of the insulating substrate and the insulating cover plate is covered with a shield conductive band covering the high-voltage resistor. Since the ringing component and switch noise generated from the secondary coil of the flyback transformer are absorbed in this shield conduction band, the high-voltage resistor affects the ringing component and switch noise. You will not receive it. Therefore, since the high-voltage resistor can be arranged close to the secondary coil of the flyback transformer, the flyback transformer can be downsized.

Further, unlike the conventional case, the responsiveness of the voltage correction performance of the flyback transformer is deteriorated by the switch noise, and the striping pattern does not occur on the screen due to the ringing component.

[0011]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same members as those in the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted. 1 and 2 show a partial configuration of a first embodiment of a flyback transformer according to the present invention.

FIGS. 1A, 1B, and 1C show the structure of the high-voltage resistor 9 incorporated in the flyback transformer of this embodiment. As shown in (a) of the figure, the high voltage resistor 9 is formed by printing on the recessed surface 20 of the recess 29 formed on the surface of the alumina substrate 19 as an insulating substrate made of an alumina material. The lead terminals 21 and 22 drawn from both ends of the high-voltage resistor 9 and the voltage-dividing terminal 24 drawn from the middle of the high-voltage resistor 9 are formed in the groove 25 formed in the side base 23 of the alumina substrate 19. It is taken out from the alumina substrate through 26 and 27.

The printed surface side of the high-voltage resistor 9 of the alumina substrate 19 is covered with an alumina lid plate 28 as an insulating lid plate made of an alumina material, and the alumina substrate 19 and the alumina lid plate 28 are the alumina substrate. The concave portion 29 of the groove 19 is filled with the resin and is integrally bonded and fixed by a resin such as epoxy, acrylic, or silicon applied to the mating surface of the alumina substrate 19 and the aluminum cover plate 28.

As shown in (b) and (c) of the same figure, the outer periphery of the integrated alumina substrate 19 and alumina cover plate 28 is longer than the length a in which the high voltage resistor 9 is formed by printing. A shield conductive band 30 is formed so as to cover the high voltage resistor 9 by vapor deposition of copper, aluminum or the like in a slightly longer width b (b> a). A ground terminal 31 is pulled out from the shield conductive band 30, and the ground terminal 31 is connected to the ground side as described later. It has a function as a shield so that it is not affected by noise and ringing components.

The high-voltage resistor 9 configured as described above is mounted on the holder 15 together with the smoothing capacitor 5 as shown in FIG. 2, and as shown in FIG. The holder 15 is attached to the coil built-in body 36 by engaging the claw 35 formed on the above with the engaging portion (not shown) of the coil built-in body 36. In this mounted state, the ground terminal 31 of the high-voltage resistor 9 is connected to the ground side of the flyback transformer, and other predetermined terminals of the high-voltage resistor 9 and predetermined terminals of the smoothing capacitor 5 are connected to desired positions. Thus, the circuit 37 of the flyback transformer shown in FIG. 8 is configured.

In the flyback transformer having the above structure, the surface of the alumina substrate 19 on which the high-voltage resistor 9 is formed by printing is covered with an alumina lid plate 28 that is an insulator. Since the shield conductive band 30 is formed on the outer circumference of 28, switch noise and ringing components generated from the secondary coil 3 of the flyback transformer are absorbed by the shield conductive band 30 and dropped to the ground. It

Therefore, the high-voltage resistor 9 built in the flyback transformer is not adversely affected by the switch noise and the ringing component, so that the response of the correction performance in the high-voltage correction circuit is improved and the screen is displayed. A striped pattern due to ringing components does not occur, and a clear screen can be obtained.

Further, since the switch noise and the ringing component are absorbed by the shield conductive band 30, it becomes possible to dispose the high voltage resistor 9 close to the secondary coil 3 of the flyback transformer, and the high voltage resistor The flyback transformer with a built-in body can be miniaturized.

A second embodiment according to the present invention is shown in FIGS. 3 (a) and 3 (b). The difference between this embodiment and the first embodiment is that in the first embodiment, the high-voltage resistor 9 is formed by printing on the recessed surface 20 of the recess 29 of the alumina substrate 19, but in this embodiment, the aluminum The concave portion 29 is not provided in the substrate 19 and the high voltage resistor 9 is formed by printing on the surface of the alumina substrate 19, while the concave portion 32 and the groove portions 25, 26, 27 through which the lead terminals 17, 21, 22 are inserted on the alumina lid plate 28 side. Is formed. The other structure is the same as that of the first embodiment, and the shield conductive layer 30 is formed on the outer periphery of the integrated alumina substrate 19 and alumina cover plate 28.

Also in the case of this embodiment, since the ringing component and the switch noise are absorbed by the shield conductive layer 30, the response of the correction performance in the voltage correction circuit is improved, and the stripe pattern due to the ringing component does not occur on the screen. The same effects as those of the first embodiment are obtained.

FIGS. 4A and 4B show the configuration of the third embodiment according to the present invention. In this embodiment, a step portion 33 is formed around the entire inner surface of the side base 23 of the alumina substrate 19 in the first embodiment, and an alumina lid plate 28 is placed on the step portion 33 to form a high voltage resistor. 9 is covered, and the other structure is the same as that of the first embodiment.

Also in the case of this embodiment, the ringing component and the switch noise are absorbed by the shield conductive band 30, so that the same effects as in the above-mentioned respective embodiments can be obtained.

FIGS. 5A and 5B show a fourth embodiment according to the present invention. In the case of this embodiment, the high-voltage resistor 9 is formed by printing on the surface of the alumina substrate 19, and the box-shaped alumina lid plate 28 is arranged so as to wrap the side surface and the printed surface of the alumina substrate 19, The height h of the alumina lid plate 28 is sufficiently large so that the ceiling surface 34 of the alumina lid plate 28 and the printed surface of the high voltage resistor 9 do not come into contact with each other. The other structure is the same as that of the first embodiment.

Also in the case of this embodiment, the ringing component and the switch noise are absorbed by the shield conductive band 30, so that the same effects as in the above-mentioned respective embodiments can be obtained.

The present invention is not limited to the above-mentioned embodiment, and various embodiments can be adopted. For example, in the third embodiment, the step portion 33 is formed over the entire circumference of the side surface of the concave portion 29 of the alumina substrate 19, but the step portion 33 is formed only on the two opposite side surfaces. The alumina lid plate 28 may be placed at the position shown by the two-dot chain line in (b). The shape of the alumina substrate 19 or the alumina lid plate 28 is not limited as long as it covers the printed surface of the high voltage resistor 9 of the alumina substrate 19 and covers the alumina lid plate 28.

Further, in each of the above embodiments, the shield conductive band 30 is formed by depositing copper or aluminum, but a conductive substance such as gold other than copper or aluminum may be deposited. In addition, a tape or metal foil made of these conductive materials may be wound around the outer circumference of the alumina substrate 19 and the alumina cover plate 28, or in a heat-shrinkable tube in which a conductive material such as aluminum is mixed. The shield conductive band 30 may be formed by inserting the substrate 19 and the alumina lid plate 28 and applying hot air to shrink the tube.

Further, although the alumina material is used as the insulating substrate and the insulating cover plate, other insulating materials may be used.

Furthermore, in each of the above-described embodiments, the width b of the shield conductive band 30 is formed to be slightly longer than the length a of the high voltage resistor 9 printed on the surface of the alumina substrate 19. However, if the shield conductive band 30 can have the function of a shield body, the width b of the shield conductive band 30 may be shorter than the length a in which the high voltage resistor 9 is formed.

[0029]

[Effect of device]

 In the present invention, an insulating cover plate is covered so as to cover the printed surface of the high voltage resistor of the insulating substrate, and a shield conductive band covering the high voltage resistor is formed around the insulating substrate and the insulating cover plate. Therefore, the ringing component and the switch noise generated from the secondary coil of the flyback transformer are absorbed in the shield conduction band. Therefore, the high-voltage resistor is not affected by the switch noise or ringing component, and the response of the voltage correction performance of the flyback transformer is deteriorated due to the switch noise, or the ringing component causes the screen to become unresponsive. Stripes will not occur.

Further, as described above, since the ringing component and the switch noise are absorbed in the shield conduction band, it is possible to bring the high voltage resistor close to the secondary coil of the flyback transformer. The built-in flyback transformer can be miniaturized.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a partial configuration of a first embodiment of a flyback transformer according to the present invention.

FIG. 2 is a perspective view showing a mode in which a high voltage resistor is mounted on a holder in the embodiment.

FIG. 3 is an explanatory diagram showing a partial configuration of a second embodiment according to the present invention.

FIG. 4 is an explanatory diagram showing a partial configuration of a third embodiment according to the present invention.

FIG. 5 is an explanatory diagram showing a partial configuration of a fourth embodiment according to the present invention.

FIG. 6 is a mounting configuration diagram of a flyback transformer.

FIG. 7 is an element configuration diagram of a high voltage resistor.

FIG. 8 is a circuit configuration diagram of a flyback transformer.

[Explanation of symbols]

 1 Flyback transformer 3 Secondary coil 6 Cathode ray tube 9 High-voltage resistor 19 Alumina substrate (insulating substrate) 28 Alumina lid plate (insulating lid plate) 30 Shield conductive band

Claims (1)

[Scope of utility model registration request] 1. A flyback transformer having a built-in high-voltage resistor for detecting a high-voltage output voltage output from a secondary coil to a cathode ray tube, wherein the high-voltage resistor is formed by printing on a surface of an insulating substrate. The insulating substrate is covered with an insulating cover plate covering the printed surface of the high-voltage resistor, and a shield conductive band covering the high-voltage resistor is formed on the outer periphery of the insulating substrate and the insulating cover plate. Flyback transformer.