JPH0314776Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention integrates a fluorescent lamp and a high-frequency lighting circuit for lighting the fluorescent lamp in an envelope equipped with a base. This invention relates to a fluorescent lamp device that can be used by directly inserting it into an incandescent lamp socket.

[Technical background of the invention and its problems]

Conventionally, the lighting circuit for this type of device generally used a chiyoke ballast type ballast, but recently, in order to make the lighting circuit smaller and lighter and improve lighting efficiency, the above-mentioned type of ballast has been used. Attempts have been made to use high frequency lighting circuits in place of choke ballast type ballasts.

As this high-frequency lighting circuit, a circuit configuration shown in FIG. 1 is considered, but in such a high-frequency lighting circuit, the high-frequency conversion circuit 101
There is a problem in that radiated noise close to the frequency generally used as radio waves is generated from circuit elements constituting the circuit, particularly inductor devices such as the output transformer 102 and the current limiting transformer 103 through which the main current flows, leading to radio wave interference. . As a measure to prevent this radiated noise, it is generally known to completely cover the area around the noise source with a metal cover and ground this cover. In a fluorescent lamp device, it is nearly impossible to ground it easily.

Moreover, if the inductor device, which is a source of noise, is hermetically covered with a cover, air permeability and heat dissipation will deteriorate, so self-heating during circuit operation will damage the core, windings, transistors, etc. of the inductor device. There is a risk that overheating will cause dielectric breakdown between the windings, magnetic flux saturation of the core, or thermal runaway of the transistor, and there is also a problem that the thermal influence on various circuit elements such as other capacitors and semiconductors will be increased.

Therefore, it is conceivable to provide ventilation holes in the circumferential surface of the cover. However, although this method ensures ventilation to the circuit elements to some extent, the noise prevention effect may not be sufficient depending on the position of the holes, and the number of manufacturing steps required to make the holes increases, resulting in higher costs. be.

[Purpose of invention]

The present invention was developed based on these circumstances, and it is possible to reduce radiation noise without interfering with the heat dissipation of circuit elements using a single conductive member, and to develop a fluorescent lamp device with a simple structure and low cost. For the purpose of providing.

[Summary of the idea]

That is, in order to achieve the above purpose, the present invention
A transparent envelope having a base, a fluorescent lamp housed in the envelope, and a high-frequency lighting circuit element for lighting the lamp that includes an inductor device on one side housed in the envelope. The placed circuit board, a bottom plate portion provided opposite to the surface of the circuit board opposite to the surface on which the circuit elements are placed, and a bottom plate portion provided partially in the circumferential direction on the outer periphery of the bottom plate portion, and the above-mentioned circuit A conductive member having a rising wall that rises toward the surface on which the element is attached, and a cover wall that is provided at the tip of the rising wall and is bent so as to cover the circuit element. The present invention is characterized in that the inductor device is disposed in a portion of the conductive member covered by the cover wall and on the outer peripheral side of the circuit board.

[Example of idea]

An embodiment of the present invention will be described below with reference to FIGS. 2 to 7.

In the figure, reference numeral 1 denotes a cover made of synthetic resin, which is formed into a bowl shape with a circumferential surface shaped like a paraboloid of revolution. A base 2 is attached to the top of one end of the cover 1, and an opening at the other end is covered with a light-transmitting synthetic resin or glass globe 3. The globe 3 has a substantially spherical shape, and the cap of the globe 3 forms an envelope 4 in the shape of a pole bulb. A curved tube-shaped fluorescent lamp 5 and a high-frequency lighting circuit 6 for lighting the fluorescent lamp 5 are integrally housed within the envelope 4. This fluorescent lamp 5 is constructed by bending a straight glass bulb with electrodes 7 sealed at both ends into a substantially U-shape at the center between both ends 8, 8 to form a curved portion 9. By bending the curved portion 9 and both end portions 8, 8 into a substantially U-shape in a direction substantially perpendicular to a plane including the U-shape, the curved portions 9 and 9 They are called saddle-shaped fluorescent lamps because their overall shape resembles a horseback saddle. A predetermined amount of mercury and an inert gas are sealed inside the bulb of the fluorescent lamp 5, and a phosphor coating is coated on the inner surface. Such a fluorescent lamp 5 is supported with its both ends 8, 8 and curved portion 9 facing the cover 1 side, and although this support structure is not shown in detail, in the case of this embodiment, Both end portions 8, 8 and bent portion 9 are connected to a pair of support walls 10, 10 led out from the top side of one end of the cover 1.
It is configured to be locked in place.

On the other hand, as shown in the block diagram in FIG. The cycle is inputted to a full-wave rectifier circuit 12 through a line filter circuit 11 for noise absorption, and the full-wave rectifier circuit 12 converts it into direct current and outputs it, and further converts this output voltage into a high-frequency converter circuit 1.
4, it is converted to a high frequency voltage and output. The high frequency lighting circuit 6 is connected to the fluorescent lamp 5 via the cap 2 and the current limiting transformer 16.

Each of the circuits 11 to 14 of the high frequency lighting circuit 6 is arranged on one surface of the flat circuit board 17, and therefore various circuit elements, that is, the high frequency conversion circuit 14 are arranged on the same surface of the circuit board 17. A current limiting transformer 16, an output transformer 18, and other circuit elements 19 such as transistors, resistors, and capacitors are attached and connected to a predetermined circuit configuration by a printed wiring layer (not shown). Of these circuit elements 16, 18, 19...
Inductor devices such as the current limiting transformer 16 and the output transformer 18, which are the main sources of noise, are arranged at positions offset toward the outer peripheral end of the circuit board 17. Further, the circuit element 1 on the circuit board 17
A conductive bottom plate part 2 made of an aluminum plate with a thickness of about 1 mm is attached to the back surface opposite to the surface on which 6, 18, 19... are arranged, with a silicone adhesive 20 interposed therebetween.
1 is in close contact with the circuit board 17, and this bottom plate portion 21 covers the entire back surface of the circuit board 17. Two parts of the outer surrounding part at both ends of the bottom plate part 21 are integrally folded back toward one side of the circuit board 17, and these folded parts 2
Covering walls 24, 24 are formed at the tips of the rising walls 23, 23 of No. 2, 22, and are spaced apart and facing each other substantially parallel to one surface of the circuit board 17. Therefore, the bottom plate portion 21 and the folded portions 22, 22 are integrally formed electrically conductive members. The rising walls 23, 23 extend from both ends of the bottom plate 21, and there are no rising walls on other parts of the periphery of the bottom plate 21. The space between the walls 23 is open. Further, the cover walls 24, 24 are spaced apart on the circuit board 17, and a gap that continues on the circuit board 17 is formed between these cover walls 24, 24. And this kind of folded part 2
2 and 22 are located corresponding to the current limiting transformer 16 and the output transformer 18 on the circuit board 17, and the rising walls 23, 23 and the cover wall 2
The inner surfaces of the transformers 4 and 24 are close to the transformers 16 and 18, and cover the current limiting transformer 16 and the output transformer 18 with the bottom plate 21 on the back side.

In addition, when attaching the bottom plate part 21 to the circuit board 17, the folded parts 22, 22 are integrally molded on both ends of the bottom plate part 21 by pressing etc. in advance.
After this, the circuit board 1 is equipped with various circuit elements 16, 18, 19, etc. from the side between the folded parts 22, 22.
7 and insert the surface of this circuit board 17 into the bottom plate part 2.
1 with silicone adhesive 20 to complete the installation. Further, reference numeral 26 in FIG. 4 is a starting circuit for the fluorescent lamp 5, and the circuit board 1
7 together with the high frequency lighting circuit 6.

According to such a configuration, the folded parts 22, 22 of the bottom plate part 21 covering the back surface of the circuit board 17 are integrally provided, and the respective walls 23, 22 of the folded parts 22, 22,
In the space surrounded by
It can cover around 18 cores. Therefore, the magnetic field generated during circuit operation can be efficiently shielded, the leakage of radiated noise is reduced, and adverse effects on surrounding equipment such as radio wave interference can be suppressed. The folded parts 22, 22 for shielding this magnetic field are formed by simply folding back the outer peripheral end of the conductive member, so there is no need for special hole-drilling work as in the past, and the individual transformers are The number of parts can be reduced compared to the case where 16 and 18 are covered with a shielding cover. Therefore, a large shielding effect can be obtained with a simple structure and a small area, contributing to cost reduction and weight reduction.

Further, the bottom plate portion 21 includes folded portions 22, 22.
Various circuit elements 16, 18 on the circuit board 17 other than
Since there is no part that covers 19...
These circuit elements 16, 18, 19... are not sealed, and especially in the case of this embodiment, the folded portion 2
Since there is a space between 2 and 22, circuit element 1
6, 18, 19... can be sufficiently ensured. Therefore, the circuit elements 16, 18, 19...
Since the heat dissipation of the circuit is not hindered, it is possible to prevent magnetic flux saturation and dielectric breakdown of transformers, as well as thermal damage to other capacitors and semiconductors, which has the advantage of increasing the reliability of circuit operation.

In addition, the inventors of the present invention
2 and 22, a lighting circuit that covers each transformer 16 and 18, a lighting circuit that simply covers only the back side of the circuit board 17 with the bottom plate part 21, and a lighting circuit that does not take any measures are placed inside the envelope 4. When the intensity of radiation noise generated from each circuit was measured during circuit operation, the results shown in FIG. 7 were obtained. The symbols A to C in FIG. 7 indicate the radiation noise of each lighting circuit in the above order.
As is clear from the figure, radiated noise can be reduced to some extent by simply attaching the bottom plate part 21 to the back surface of the circuit board 17, but when the folded parts 22 are added to this, the radiated noise sharply increases. It was observed that the folded portions 22, 22
It can be seen that the magnetic field shielding effect is sufficiently exhibited.

When such folded portions 22, 22 are provided, the tips of the covering walls 24, 24 are brought into contact with each other as in the other embodiment shown in FIG. 8, and a loop is formed around each transformer 16, 18. It may be covered in a shape. When the radiation noise was measured at this time, it was found that it decreased further as shown by the symbol A' in Fig. 7, and this was because the transformers 16 and 18 were covered in a loop to shield the magnetic field. This is thought to be because the effect is further enhanced.

In the embodiments described above, the fluorescent lamp has a saddle shape, but it may be U-shaped, for example, and the shape of the envelope is not limited to the ball bulb shape.

[Effect of idea]

As detailed above, in the present invention, the conductive member surrounding the circuit elements of the circuit board is connected to a bottom plate portion provided opposite to the surface of the circuit board opposite to the surface on which the circuit elements are installed; A rising portion that is partially provided along the circumferential direction on the outer periphery and rises toward the surface on which the circuit element is attached, and a rising portion that is provided at the tip of this rising portion and is bent so as to face away from the bottom plate portion. and a cover portion of the circuit board, and the inductor device of the circuit element is disposed in a portion covered by the cover portion and on the outer peripheral side of the circuit board. Accordingly, the magnetic field generated from the inductor device during circuit operation can be efficiently shielded by the bottom plate portion, the rising portion, and the cover portion of the conductive member, and radiation noise can be suppressed to a low level. Further, since the rising portion is not provided all around the bottom plate portion but is formed partially, the conductive member is left open on the sides, and therefore does not impede heat dissipation from the circuit elements. Moreover, the rising part and the cover part that contribute to shielding the magnetic field can be simply extended from the bottom plate part of the conductive member and folded back, so no special post-processing or parts are required, and the number of parts can be reduced and the structure It becomes possible to simplify the process, reduce costs and reduce weight.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a high-frequency lighting circuit showing the technical background of the invention, Figs. 2 to 7 show an embodiment of the invention, Fig. 2 is a sectional view of the entire device, and Fig. 3 is a circuit diagram of a high-frequency lighting circuit showing the technical background of the invention. FIG. 4 is a block diagram of the high-frequency lighting circuit, FIG. 5 is a plan view of the high-frequency lighting circuit, FIG. 6 is a cross-sectional view taken along the line in FIG. 5, and FIG. 8 is a characteristic diagram, and FIG. 8 is a sectional view showing another embodiment of the present invention. 2...Base, 4...Envelope, 5...Fluorescent lamp, 6...High frequency lighting circuit, 16, 18, 19...
...Circuit element (current limiting transformer, output transformer), 1
7...Circuit board, 21...Bottom plate portion, 22...Folding portion, 23...Rising wall, 24...Covering wall.

Claims (1)

[Scope of utility model registration request] A translucent envelope having a base, a fluorescent lamp housed in the envelope, and a high-frequency lighting circuit element for lamp lighting housed in the envelope and including an inductor device on one side are arranged. a circuit board, a bottom plate portion provided opposite to the surface of the circuit board opposite to the surface on which the circuit elements are disposed, and a bottom plate portion provided partially along the circumferential direction on the outer periphery of the bottom plate portion; a conductive member having a rising portion rising toward the surface on which the element is attached, and a cover portion provided at the tip of the rising portion and bent so as to cover the circuit element; A fluorescent lamp device characterized in that an inductor device is disposed in a portion covered by the cover portion of the conductive member and on the outer peripheral side of the circuit board.