JPS58164189A - High frequency heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-frequency heating device such as a so-called microwave oven, and its purpose is to improve the strength of the operation panel section and digital display section, improve resistance to static electricity noise, and to improve resistance to static electricity noise from inside the device. It is an object of the present invention to provide a high-frequency heating device that is safe and of high quality by reducing unnecessary radiation that occurs, and to provide a high-frequency heating device that is highly productive by simplifying the structure.

Conventionally, this type of high-frequency heating device has a digital display section consisting of a display tube and a resin or glass translucent or transparent plate (smoke plate) covering the display tube in the operation panel section, and a microcomputer for inputting instruction signals. The smoke plate and the keyboard were fixed by separate metal fixing plates. This resulted in a complicated structure and low productivity. Furthermore, since the entire surface of the operation panel is not covered with metal, the structure cannot prevent unnecessary radiation generated from inside the device, and discharge sparks due to static electricity from the gaps between the metal parts can affect the electronic components inside the operation panel. However, it had low resistance to static electricity noise. Furthermore, since the structure did not hold down the entire surface of the smoke plate, there was also a problem in terms of the strength of the smoke plate.

A conventional example will be specifically described below.

FIG. 6 shows a conventional example of an operation panel, in which a smoke plate 26 covering a display tube 21 is attached with smoke plate holding plates 27 provided on each side of the display tube 21 using screws. A smoke plate was sandwiched between the frame 28 and the smoke plate was fixed.The keyboard 13 was held down by a metal back plate 26 and screws, and the keyboard was sandwiched between the back plate 26 and the operation/channel frame 28. For this reason, the smoke plate is held down only on both sides, so if you press the center, it will become sticky and the strength will be weak, and since a boss is required on both sides of the smoke plate to screw the smoke plate holding plate, the smoke Width A of the plate 26: Only a narrow one can be fixed.Since it does not cover the entire operation/channel frame, static electricity is discharged from the gap to the internal electronic circuit, leading to malfunction of the microcomputer.Also, from the gap, the above-mentioned Unnecessary radiation from the high frequency oscillator of the high frequency converted inside the high frequency oscillator goes out of the device and affects other wireless products.

The present invention solves the above-mentioned conventional drawbacks, and consists of a single metal plate (back plate) that covers the entire inside of the operation panel, and a smoke plate and a keyboard are sandwiched between the back plate and the operation panel frame. This configuration has the effects of reducing unnecessary radiation due to the back plate, improving electrostatic noise resistance, and reinforcing the smoke plate.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIGS. 1 and 2 are diagrams showing the configuration of a high-frequency heating device, in which a high-frequency oscillator 1 that oscillates microwaves of 245 Q MHz is coupled to a metal waveguide 2 and an antenna 3. The high frequency wave emitted from the high frequency oscillator 1 into the waveguide 2 propagates inside the waveguide 2, and then further into the heating chamber 4.
radiated within.

The high frequency waves radiated into the heating chamber 4 are absorbed by the food 6 placed inside the heating chamber 4, and 6% of the food is absorbed from the inside of the food 5.
Dielectric heating. In addition, the island frequency oscillator 1ri is self-heated due to internal loss, and is constantly cooled by the blower fan 6 during one oscillation to prevent failure. A door 7 that can be opened and closed is provided on the front side of the heating chamber 4, and an electrical parts room 8 is provided on the side surface of the heating chamber 4. ,
A high voltage capacitor 1o is located there. An operation panel 11 is configured on the front of the electrical component room 8, and a digital display section 12,
It consists of 13 keyboards, etc.

Figure 3 shows a control circuit for the high-frequency heating device, and one end of the power plug 14 is used to prevent short circuits and ground faults in the electrical components that make up the high-frequency heating device, as well as to prevent excessive leakage of microwaves during welding of interlocks, which will be described later. Therefore, it is connected to the fuse 16 which is blown by the operation of the short switch 18. Furthermore, the fuse 16 is connected to the primary winding of the high voltage transformer 9 via two interlock switches 16 and a relay 17 whose contacts open and close when the door 7 opens and closes.

Further, the relay 17 is turned on and off by a heating start signal and a heating completion signal input to a microcomputer (hereinafter abbreviated as microcomputer) 19 through the keyboard 13. Blown 1 and 6 are connected to both ends of the primary winding of the high voltage transformer 9.
A short switch 18 that makes the entire circuit inoperable when the interlock 16 is welded, and a lamp 20 that illuminates the inside of the heating chamber 4 are connected. The other terminal of the power plug 14 is connected to the primary winding of the high voltage transformer 9. A display tube 21 is connected to the microcomputer 19 to indicate the contents of commands inputted to the microcomputer 19 through the keyboard 13 and to display a clock display. The AC power applied to the high-voltage transformer 9 is stepped up by the high-voltage transformer 9 to become high-voltage power, and the high-voltage power is converted into high-voltage DC power that is voltage doubled and rectified by a voltage doubler rectifier circuit composed of a high-voltage capacitor 1o and a high-voltage diode 22. converted. The high-voltage direct current power is a high-voltage switch 23 that opens and closes at certain intervals to vary the amount of high-frequency output.
is supplied to the high frequency oscillator 1 via. The opening and closing of this high voltage switch 23 is controlled according to the output mode input to the microcomputer 19 via the keyboard 13. The high-voltage DC power supplied to the high-frequency oscillator 1 is converted into high-frequency power inside the high-frequency oscillator 1 and radiated from the antenna 3. Thereafter, the high frequency heats the food 6 through the process described above.

Further, the high voltage transformer 9 is provided with a heater winding 24, and the heater winding 24 is connected to the heater of the high frequency oscillator 1 by a lead wire to heat the heater. As mentioned above, the high frequency wave converted inside the high frequency oscillator 1 is radiated from the antenna 3, but at this time, a part of the high frequency wave is propagated from the heater to the lead wire and is radiated from the lead wire as unnecessary radiation.

In addition, when a person uses the device, he or she touches the operation panel 11°, especially around the keyboard, and at this time, if noise enters the microcomputer 19 through the keyboard 13 due to static electricity in the human body, it may cause a malfunction of the microcomputer 19 or an incorrect display on the display tube 21. Become. Also, if there is a spark directly to the electronic circuit, the microcomputer 19
It also leads to the destruction of

FIG. 4 shows the operation panel of the present invention, with the smoke plate 26'
The keyboard 13 is held down by a back plate 29 made of a single piece of metal and fixed with screws.
The smoke plate 2i and the keyboard 13 are fixed by sandwiching the smoke plate 2i and the keyboard 13. Further, since the outer shape of the smoke plate 26' is larger than the square hole 29-1 of the back plate, the four sides of the smoke plate 26' can be pressed down by the back plate, and the strength can also be improved.

Since the back plate 29 is grounded to the main body via the short-circuit plate 30, if static electricity is supplied from the human body during use, all of it will be discharged to the back plate 29 and will not affect the electronic components inside the operation panel. In addition, the above-mentioned high frequency oscillator 1
The back plate can also prevent unnecessary radiation from escaping the device. In addition, there is no need to make a boss next to the smoke plate 26' whose edges are bent for reinforcement around the back plate 29 and fix the smoke plate 25'. is made and the back plate 29 is fixed. Therefore, it is also possible to configure the smoke plate 25' to have a wide width.

FIG. 6 shows another embodiment of the present invention in which the keyboard 13 is smaller than the operation panel frame 28.

The aforementioned unnecessary radiation is prevented by combining the metal display panel 31 and the back plate 29 and covering the entire front surface of the operation panel 11 with metal. The display panel 31 has a claw 31- provided on the display panel 31 from the outside on the operation panel frame 28.
1 into a rectangular through hole 28-1 provided around the operation panel frame 28, and is fixed by folding it up.

In addition, as mentioned above, the small through hole 2 is provided in the operation panel frame 28.
8-1 is provided, static electricity from the human body is transferred to the through hole 2.
In order to prevent sparks from entering the electronic components inside the operation panel 11 through the through-hole 28-1, a 7-lunge 29-2 is installed on the back plate 29 so as to cover the through-hole 28-1.
is attached to discharge static electricity to the back plate 29.

Moreover, by configuring as described above, it is possible to fix the keyboard 13 and the smoke plate 26' with a single metal plate, and it is possible to provide a high-frequency heating device with high productivity.

As described above, according to the present invention, the following effects can be obtained.

(1) A safe high-frequency heating device with improved strength of the digital display section can be provided.

(b) It is possible to provide a high frequency heating device that is free from failure due to static electricity noise.

@) It is possible to prevent unnecessary radiation emitted from the inside of the device from going outside the device, and it is possible to provide a high-frequency heating device that is less affected by noise etc. on other wireless devices.

(4) Since the smoke plate and the keyboard can be fixed in one piece, it is possible to provide a high-frequency heating device with high productivity.

(b) It becomes possible to attach a wide smoke plate, and it is possible to provide a high-frequency heating device with an improved design.

[Brief explanation of drawings]

Fig. 1 is an external perspective view of a high-frequency heating device that is an embodiment of the present invention, Fig. 2 is a front sectional view of the device, Fig. 3 is a control circuit diagram of the device, and Fig. 4 is an operation of the device. FIG. 6 is an exploded perspective view of an operation panel according to another embodiment of the present invention, and FIG. 6 is an exploded perspective view of a conventional operation panel. 1...High frequency oscillator, 4...Heating chamber,
8... Electrical parts room, 11... Operation panel, 13... Keyboard, 19... Microcomputer, 25, 25... Smoke board , 26.2
9...Back board, 28...Operation panel frame, 3o...Short circuit board, 31...Display panel. Name of agent: Patent attorney Toshio Nakao and one other person I1
Figure 2 q 113 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] (1) An operation panel section having an operation panel frame, a translucent or transparent smoke plate made of resin or glass that covers the display tube of the operation panel section, and a keyboard for inputting instruction signals to a control circuit including a microcomputer. and a single metal back plate for fixing the smoke plate and the keyboard, and the high frequency heating device is configured to fix the smoke plate and the keyboard by sandwiching them between the back plate and the operation panel frame. . (b) The high-frequency heating device according to claim 1, wherein the back plate is grounded via a shorting plate. 1.3) The high frequency heating device according to claim 1, wherein the smoke plate is fixed by utilizing the elasticity of the elastic plate.