KR19990020616A - Secondary Electromagnetic Radiation Prevention Grid of Microwave Oscillation Tube for Microwave Oven - Google Patents

Abstract

The present invention relates to a secondary electron emission prevention grid of an ultra-high frequency oscillation tube for a microwave oven, and the present invention provides a secondary electron emission prevention means on the lower surface thereof, that is, toward the cathode 132 as the first grid 200, The secondary electron emission preventing means is preferably hafnium (Hf) or platinum (Pt) or osmium (Os) metal film (300).

According to the present invention, if hafnium (Hf) or platinum (Pt) or osmium (Os) metal film 300 is formed on the lower surface of the first grid 200, since hafnium or platinum or osmium metal is an electronically stable metal, Essentially blocking electrons from radiating toward the cathode 132, some of the hot electrons emitted as the first grid 134 is heated are released towards the second grid 142 and attracted to the anode 146 to produce Contributes to the improvement, and the rest hits the second grid 142 to generate heat, thereby reducing noise and smoothing the flow of electrons, thereby improving output efficiency.

Description

Secondary Electromagnetic Radiation Protection Grid of Microwave Oscillation Tube for Microwave Oven

The present invention relates to an ultra-high frequency oscillation tube for a microwave oven, and more particularly, to a grid capable of preventing emission of secondary electrons between a first grid and a cathode.

As is well known, magnetron is employed as a microwave oven for microwaves. However, such a conventional magnetron for a microwave oven requires a high voltage transformer and a high pressure diode according to a high pressure driving, and thus, there is a problem in safety, and a magnet is needed because it adopts a resonance method by electromagnetic movement in an electromagnetic field. There was a problem that the weight is heavy and the manufacturing cost is high.

To solve this problem, Klystron disclosed in U.S. Patent No. 5,541,391 is used as an ultra-high frequency oscillation tube, but the microwave oven employing such Klystron still applies high voltage of DC 4KV, so the input terminal is a separate insulation member. Since the product must be insulated from the main body, the product is heavy and the manner of movement of electrons is complicated, the cooling structure must be complicated, the structure having a large number of cavities, the electron beam focusing structure is required, and a magnet is required. Since it was necessary, the structure had a complicated disadvantage.

Accordingly, the present applicant has proposed a microwave microwave tube for microwave oven in Korean Patent Application No. 97-36327 which is simple in structure and can eliminate the risk of high voltage and achieve light weight. As shown in FIG. 1, the ultra-high frequency oscillation tube is mounted on the upper surface of the heater 120 by placing the cathode 132 as a ring-shaped disk-shaped electron radiator on the indirect heating method by the heat generation of the heater 120. When the cathode 132 is heated to about 600-1200 ° C., the hot electrons are emitted, and the emitted hot electrons are disposed between the first grid 134 and the cathode 132 arranged at predetermined intervals on the cathode 132. It is focused by the bias voltage Vb of 50-100V DC applied and passes through the second grid 142 to the operating voltage V of 500-700V DC applied between the anode 146 and the cathode 132. Accelerated by the potential difference, surface current is induced between the anode 146 to form a microwave, and the formed microwave is radiated through an antenna (not shown) formed through the center of the anode 146.

However, in the conventional microwave microwave tube, the electrons emitted toward the second grid 142 of the hot electrons emitted while the first grid 134 is heated are attracted to some anode 146 to contribute to the improvement of the output. And the rest hit the second grid 142 to generate heat, while the electrons radiated toward the cathode 132 (so-called secondary electrons) are accelerated toward the cathode 132 by the potential difference and are emitted from the cathode 132. Since it hits and hinders the flow of electrons, there was a problem of reducing the overall efficiency.

Accordingly, the present invention is to provide a grid and a method capable of preventing the emission of secondary electrons emitted toward the cathode of the hot electrons emitted while the first grid is heated.

As a means for achieving the above object, the method of preventing secondary electron emission of the microwave oven tube of the present invention to prevent the emission of secondary electrons emitted toward the cathode of the thermal electrons emitted while the first grid is heated, Secondary electron emission preventing means is provided on the lower surface of the first grid.

As an embodiment of the present invention, the secondary electron emission preventing means is preferably hafnium or platinum or an osmium metal film.

According to the present invention, since an electronically stable hafnium or platinum or osmium metal film is coated on the lower surface of the first grid, emission of secondary electrons toward the cathode is prevented, thereby providing an effect of improving output efficiency.

1 is a schematic diagram for explaining the operation of a conventional ultra-high frequency oscillation tube for a microwave oven,

Figure 2 is a schematic diagram for explaining the operation of the microwave oven for microwave oven according to the present invention.

Explanation of symbols for main parts of the drawings

120: heater 132: cathode

134,200: first grid 142: second grid

146: anode 300: secondary electron emission prevention means

Hereinafter, a secondary electron emission preventing grid and a method of the microwave microwave oscillation tube according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. It was staged.

As shown in Fig. 2, the secondary electron emission preventing grid 200 of the present invention is provided as a first grid on its lower surface, i.e. toward the cathode 132, secondary electron emission preventing means.

In a preferred embodiment of the present invention, the secondary electron emission preventing means provides a hafnium or platinum or osmium metal film 300 on the lower surface of the first grid 200.

When the hafnium, platinum or osmium metal film 300 is formed on the lower surface of the first grid 200, since the hafnium, platinum or osmium metal is an electronically stable metal, the electrons are radiated toward the cathode 132. Thus, some of the hot electrons emitted while the first grid 134 is heated are discharged toward the second grid 142 and attracted to the anode 146 to contribute to the improvement of the output, and the rest to the second grid 142. It hits and generates heat.

As described above, the secondary electron emission preventing grid of the microwave microwave tube for microwave oven according to the present invention is a first grid adjacent to the cathode, and on the lower surface thereof, an electronically stable metal is coated with hafnium or platinum or osmium to emit secondary electrons toward the cathode. By fundamentally preventing this in a simple manner, there is an effect of reducing the noise and smoothing the flow of electrons to improve the output efficiency.

Claims (2)

In the secondary electron emission prevention grid of the microwave oven tube for microwave, Microwave oscillation tube for microwave oven, characterized in that the secondary electron emission preventing means is provided on the lower surface of the first grid to prevent the emission of secondary electrons emitted toward the cathode of the hot electrons emitted while the first grid is heated. Secondary electron emission prevention grid. The secondary electron emission preventing grid of the microwave oven for microwave oven according to claim 1, wherein the secondary electron emission preventing means is hafnium (Hf) or platinum (Pt) or osmium (Os) metal film.