JPH05109476A - Microwave oven - Google Patents

Abstract

PURPOSE:To increase the radio wave leakage preventing effect and surely improve the visibility in a heated cooking chamber. CONSTITUTION:A radio wave shielding body 28 is constituted of a transparent plate 32, a meshy black backing layer 33 formed on the inside face of the heated cooking chamber 12 of the transparent plate 32, and a conductor pattern 34 formed on the backing layer 34. The conductor pattern 34 and the backing layer 33 are made meshy, the outside black backing layer 33 has less light reflection than the conductor pattern 34, thus visibility is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave oven having an improved door leakage prevention structure.

[0002]

2. Description of the Related Art Generally, in a microwave oven, a transparent window is provided on the door so that a user can look into the cooking chamber from the outside of the door. The transparent window section is provided with an inner barrier (a radio wave shield) formed by covering a radio wave shielding punching plate integrally formed on the main frame of the door with a glass plate.

However, in the above-mentioned conventional structure, the size of the holes of the punching plate is limited due to the restriction of radio wave leakage, and the number of the holes (density) is also limited due to the restriction of punching. Therefore, when looking into the cooking chamber, the punching plate inevitably comes into contact with the eyes, making it difficult to see the cooking chamber.

As a structure for solving such a problem,
As shown in FIGS. 8 and 9, a mesh-shaped conductor pattern 2 is formed on one surface of the glass plate 1 by, for example, electroless plating to form an inner barrier 3, and the inner barrier 3 is attached to the main frame of the door. It is possible that

With this structure, since the mesh-shaped conductor pattern 2 is formed, there is no restriction on punching processing, the number of holes (density) can be increased, and the visibility to the heating and cooking chamber can be increased accordingly.

[0006]

However, in the above-mentioned conventional case, although the visibility to the cooking chamber is good when the surroundings of the microwave oven are relatively dark, the user sees that the surroundings of the microwave oven are bright. Depending on the angle, the light outside the cooking chamber may be reflected by the conductor pattern 2 to reduce the visibility of the cooking chamber.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a microwave oven capable of reliably improving the visibility in the heating and cooking chamber while enhancing the effect of preventing radio wave leakage.

[0008]

The microwave oven of the present invention comprises:
In a configuration in which a radio wave shield is attached to a main frame of a door that opens and closes a cooking chamber, the radio wave shield is a transparent plate,
Characteristic in that the transparent plate is provided with a mesh-shaped black base layer formed on the inner surface of the heating and cooking chamber and a conductor pattern formed in a mesh shape on the base layer. (The invention of claim 1).

Further, in the microwave oven of the present invention, a radio wave shield is attached to a main frame of a door for opening and closing the heating and cooking chamber, wherein the radio wave shield is a transparent plate and the heating and cooking chamber of the transparent plate. The present invention is characterized in that it is provided with a mesh-shaped conductor pattern formed on the outer surface and a black-colored coating layer formed in a mesh shape so as to cover the conductor pattern. Invention of Item 2).

[0010]

According to the first aspect of the invention, since the conductor pattern has a mesh shape, it is possible to effectively prevent electric wave leakage.
Moreover, unlike the case of the punching plate, there are no restrictions on the punching process, the number of holes (density) can be increased, and the visibility is generally improved. When a user views the microwave oven, the radio wave shield has a transparent plate, a black base layer, and a conductor pattern arranged in order from the outside of the heating and cooking chamber. Only the underlayer is visible, not the conductor pattern. Further, since the coating layer has a blackish color, reflection is unlikely to occur, and the problem that the conductor pattern is reflected and the inside of the heating and cooking chamber is difficult to see does not occur.

According to the second aspect of the present invention, since the conductor pattern has a mesh shape, the electric wave can be effectively leaked. Moreover, unlike the case of the punching plate, there are no restrictions on the punching process, the number of holes (density) can be increased, and the visibility is generally improved. Further, when the microwave oven is viewed by the user, in the radio wave shield, the black coating layer, the conductor pattern, and the transparent plate are arranged in this order from the outside of the cooking chamber. Only the conductor pattern is visible, not the conductor pattern. Further, since the coating layer has a blackish color, reflection is unlikely to occur, and the problem that the conductor pattern is reflected and the inside of the heating and cooking chamber is difficult to see does not occur.

Further, since the conductor pattern is formed on the outer side surface of the transparent plate, the cooking container which is put into and taken out of the heating and cooking chamber does not hit the conductor pattern portion and the conductor pattern may be damaged. Absent.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. First, in FIG.
Inside the main body 11 of the microwave oven, the cooking chamber 1
Two are provided. The front opening of the heating and cooking chamber 12 is opened and closed by a door 13. Also,
An operation panel 14 is arranged on the right side of the front surface of the range main body 11. A display unit 15 and various switches 16 are arranged on the operation panel 14.

A magnetron (not shown) is provided on the right outside of the cooking chamber 12 in the range main body 11. When the magnetron is driven to oscillate, microwaves are supplied into the heating cooking chamber 12 and the heating cooking chamber 1
The food (not shown) housed inside 2 is irradiated and the food is cooked in a microwave oven.

A drive shaft 17 for driving a rotary table (not shown) on which food is placed is provided at the bottom of the cooking chamber 12 so as to project therefrom. The drive shaft 17 is rotationally driven by a motor (not shown). A heater 18 for oven cooking is provided on the ceiling of the heating and cooking chamber 12.

The door 13 is provided with a rectangular transparent window portion 19 through which the inside of the cooking chamber 12 can be seen. Hereinafter, the structure of the transparent window portion 19 will be described in detail. That is, in FIG. 1, an outer barrier 21 made of, for example, a glass plate is attached to the upper surface of the metal main body frame 20 of the door 13. A flange portion 22 is formed on the entire inner periphery of the main body frame 20 located inside the outer barrier 21.

The flange portion 24 of the contact plate 23 is fixed to the flange portion 22 by welding, and thus the contact plate 23 is integrally provided on the main body frame 20. A space surrounded by the body frame 20 and the contact plate 23 constitutes a choke groove 25. Also, the body frame 20
A radio wave transmitting door cover 26 is provided in an opening between the contact plate 23 and the outer peripheral portion of the contact plate 23. A door sash 27 is provided on the outer peripheral portion of the main body frame 20.

An inner barrier 28, which is a radio wave shield, is adhered to the rear surface of the flange 24 of the contact plate 23 by, for example, a silicone adhesive 29, and is attached to the main body frame 20 by a screw 30. The inner barrier 28 is also attached to the body frame 20 by being pressed and held by 31 as well.

As shown in FIGS. 2, 3 and 5, the inner barrier 28 is a transparent plate such as a glass plate 32.
This is a configuration including the base layer 33 and the conductor pattern 34. The base layer 33 is made of a black epoxy adhesive and is formed in a mesh shape on the inner surface of the glass plate 32 inside the cooking chamber 12. Then, a conductor pattern 34 is formed on the underlayer 33 by electroless plating or screen printing of a conductive paint.

The thickness dimension of the conductor pattern 34 is set to, for example, about 0.2 μ. As shown in FIG. 3, in the conductor pattern 34, the line width dimension A of the linear portions 35 forming the mesh, that is, the grid is set to about 40 μ, and the interval pitch B of each line is set to about 140 μ, for example. There is. Further, the line width dimension C of the frame-shaped portion 36 of the conductor pattern 34 arranged at the edge of the glass plate 32 is
For example, it is set to about 80 μ.

In the above structure, the microwave is applied to the food by driving the magnetron to perform the range cooking. In this case, a part of the microwave is radiated to the door 13 side, but the microwave is sequentially attenuated by the contact plate 23, the choke groove 25, the front plate portion 11a of the range main body 11 and the like shown in FIG. So it doesn't leak outside.

The microwave applied to the transparent window portion 19 is shielded by the conductor pattern 34 of the inner barrier 28. The microwave on the conductor pattern 34 is shielded by the contact between the frame-shaped portion 36 of the conductor pattern 34 and the main body frame 20.

According to this embodiment having such a structure, since the conductor pattern 34 has a mesh shape, it is possible to effectively prevent electric wave leakage. Moreover, unlike the case of the punching plate, there are no restrictions on the punching process, the number of holes (density) can be increased, and the visibility is generally improved.

When the user sees the microwave oven, the inner barrier 28 has a configuration in which the glass plate 32, the black base layer 33, and the conductor pattern 34 are arranged in this order from the outside of the cooking chamber 12. , Only the black base layer 33 can be seen through the glass plate 32, and the conductor pattern 3
I can't see 4. Further, since the underlayer 33 has a blackish color, reflection is unlikely to occur, and the conductor pattern is reflected so that it is difficult to see the inside of the heating and cooking chamber.
Since the number of holes can be increased and the reflection can be eliminated in this way, the visibility into the cooking chamber 12 is surely improved.

In particular, since the underlayer 33 is made of an adhesive material, the conductor pattern 34 is less likely to be peeled off from the glass plate 33, and the radio wave shielding effect can be stably maintained.

FIG. 6 shows a second embodiment of the present invention. In this embodiment, a transparent protective layer 37 is fixed on a conductor pattern 34 with an adhesive 38. According to the second embodiment, it is possible to more effectively prevent the conductor pattern 34 from being damaged. In this case, if the protective layer 37 is made of a thermosetting resin or the like so that the protective layer 37 itself has adhesiveness, the adhesive 38 can be omitted.

Next, FIG. 7 shows a third embodiment of the present invention. In the third embodiment, the structure of the inner barrier 41, which is a radio wave shield, is slightly different from that of the first embodiment. That is, the inner barrier 41 includes a glass plate 42 that is a transparent plate, a conductor pattern 43, and a coating layer 44. The conductor pattern 43 is the glass plate 42.
The outer surface (on the side opposite to the cooking chamber 12) is formed in a mesh shape by electroless plating or screen printing of a conductive paint.

On the conductor pattern 43, a mesh-like covering layer 44 is formed so as to cover the conductor pattern 43. The coating layer 44 is made of an epoxy material that is black and has oxidation resistance.

According to the third embodiment, since the conductor pattern 43 has a mesh shape as in the second embodiment, the electric wave leakage can be effectively achieved. Moreover, unlike the case of the punching plate, there are no restrictions on punching,
The number of holes (density) can be increased, and the visibility is generally improved.

When the user looks at the microwave oven, in the inner barrier 41 which is a radio wave shield, the cooking chamber 1
2 From the outside, the black coating layer 44, the conductor pattern 43, and the glass plate 42 are arranged in this order.
Only the black coating layer 44 is visible, but the conductor pattern 43 is not visible. Further, since the coating layer 44 has a blackish color, reflection is unlikely to occur, and the problem that the conductor pattern 43 is reflected and the inside of the cooking chamber 12 is difficult to see does not occur. In this way, the number of holes can be increased and the reflection can be eliminated, so that the visibility into the cooking chamber 12 is surely improved.

Further, since the conductor pattern 43 is formed on the outer surface of the glass plate 42, the cooking container which is put into and taken out of the heating and cooking chamber 12 does not hit the conductor pattern 43 portion, and the conductor pattern 43 is damaged. There is nothing to do.

In particular, since the coating layer 44 is made of an oxidation resistant material, it is possible to effectively prevent the conductor pattern 43 from being oxidized, which also prevents the conductor pattern 43 from being damaged, and generally maintains the radio wave shielding effect in a stable manner. be able to.

In each of the above embodiments, the glass plate is illustrated as the transparent plate, but the transparent plate may be a transparent plastic plate. In addition, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

[0034]

According to the first aspect of the present invention, a radio wave shield is attached to a main frame of a door for opening and closing the heating and cooking chamber, wherein the radio wave shield is a transparent plate and the heating and cooking chamber of the transparent plate. A black-colored underlayer formed on the inner surface and having a mesh-like conductor pattern formed on the underlayer, and a conductive pattern formed in a mesh pattern on the underlayer. As a result, the base layer and the conductor pattern forming the radio wave shield can be formed into a thin film as compared with the conventional metal punching plate, so that there is little influence that the thickness hinders the visibility even when viewed from the perspective direction. Therefore, the visibility of the heating and cooking room is further improved. Further, it is possible to prevent a decrease in visibility due to reflection, and thus it is possible to reliably improve the visibility in the heating and cooking chamber.

According to a second aspect of the present invention, a radio wave shield is attached to a main frame of a door that opens and closes the cooking chamber, wherein the radio wave shield is a transparent plate and the transparent plate is provided outside the cooking chamber. A mesh-shaped conductor pattern formed on the surface, and a black coating layer formed in a mesh shape so as to cover the conductor pattern. With this, in addition to the same effect as described above, by forming the conductor pattern in a mesh shape on the outer surface of the transparent plate, it is possible to hit the cooking container etc. which is put in and out of the heating cooking chamber. It is possible to obtain an excellent effect that the accident of loss of the conductor pattern can be eliminated.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a main part showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional side view partially showing an inner barrier.

FIG. 3 is a vertical sectional rear view partially showing the inner barrier.

FIG. 4 is a perspective view of a microwave oven.

FIG. 5 is a front view of the inner barrier.

FIG. 6 is a view corresponding to FIG. 2 showing a second embodiment of the present invention.

FIG. 7 is a diagram corresponding to FIG. 2 showing a third embodiment of the present invention.

FIG. 8 is a view corresponding to FIG. 3 showing a conventional example.

FIG. 9 is a view corresponding to FIG.

[Explanation of symbols]

11 is a range main body, 12 is a cooking chamber, 13 is a door, 19
Is a see-through window, 20 is a main frame, 28 is an inner barrier (electromagnetic wave shield), 32 is a glass plate (transparent plate), 33 is a base layer, 34
Is a conductor pattern, 37 is a protective layer, 41 is an inner barrier (electromagnetic wave shield), 42 is a glass plate (transparent plate), 43 is a conductor pattern, and 44 is a coating layer.

Claims (2)

[Claims] 1. A radio wave shield is attached to a main frame of a door for opening and closing a cooking chamber, wherein the radio wave shielding body is formed on a transparent plate and a surface of the transparent plate on the inside of the heating cooking chamber. A microwave oven comprising a black-colored base layer having a mesh shape and a conductor pattern formed on the ground layer in a mesh shape. 2. A radio wave shield is attached to a main frame of a door that opens and closes the cooking chamber, wherein the radio wave shielding body is formed on a transparent plate and a surface of the transparent plate outside the cooking chamber. A microwave oven comprising a mesh-shaped conductor pattern and a black coating layer formed in a mesh shape so as to cover the conductor pattern.