DOOR FOR MICROWAVE OVEN
This application claims the benefit of Korean Patent Application Nos. 2002- 13058, filed on March 11, 2002; 2002-14210, filed on March 15, 2002; 2002-14212, filed on March 15, 2002; and 2002-22546, filed on April 24, 2002, which are hereby incorporated by reference for all purposes as if fully set forth herein.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention
relates to a microwave oven, and more particularly, to a door for selectively
closing a front surface of a microwave oven.
Discussion of the Related Art
Generally, microwave ovens such as those illustrated in Figure 1 include a
door 2 arranged on a front surface of the microwave oven body 1. Using a door
handle 3, the door 2 may be used to open and close a cooking chamber provided
within the body 1. Microwaves may be generated by various electrical devices
accommodated in a device chamber provided in one side of the microwave oven body
1 and behind the controller 5.
Referring to Figures 1 and 2, the controller 5 further includes a control panel 6
example, a display portion 7a provided as a pass-through hole, a key portion 12
including a plurality of operation keys, operating buttons 13 and 13a, and the like.
A key pad 11 is provided at a front surface of pass-through hole 7a and a display
cover 8 is provided at a rear surface of pass-through hole 7a. Generally, both the
key pad 11 and display cover 8 are formed of a transparent material.
Referring to Figure 2, a substrate 10a is provided behind the control panel 6,
opposite the pass-through hole 7a, and supports a display 10 (e.g., LED, LCD, NFD,
etc.). As the display 10 is smaller in size than the pass-through hole 7a, a gap is
formed between the two components. Accordingly, a display holder 9 may be
arranged between the display cover 8 and the display 10 to fill a space created by the
gap-
The key pad 11, provided on one region on the front of the control panel 6,
shields the key portion 12, and includes printed information corresponding to
different operation keys included within key portion 12. Accordingly, the printed
information meaningfully defines, to a user, the operation each operation key may
initiate. Return spring 13s allows for the operation ofthe operation button 13.
In the microwave oven illustrated in Figures 1 and 2, however, controller 5 is
provided on one side of the microwave oven and in front of the device chamber.
Disadvantageously, a portion of device chamber located between the various
electrical devices and the controller 5 is inefficiently used and a portion of the front
surface of the microwave body 1 is dedicated to the controller 5. Moreover, since
the controller 5 is provided in front the device chamber, a user may operate the
operation buttons 13 or the key part 12 when door 2 is opened. If a sensing device,
capable of sensing whether the door 2 is open or closed, is out of order, a safety issue
arises in that the open microwave oven may be operated by the user.
SUMMARY OF THE INVENTION
An advantage of the present invention, devised for solving the foregoing
problems, provides a door of a microwave oven permitting efficient use of a space of
the microwave oven.
Another advantage of the present invention provides a door capable of
preventing wrongful operation of a microwave oven.
The foregoing advantages of the present invention may be achieved by
providing a door on a microwave oven and a control unit arranged in a predetermined
portion of the door. In one aspect of the present invention, the control unit enables a
user to operate the microwave oven. In another aspect of the present invention, the
door may, for example, include a door unit capable of selectively opening and closing
a cooking chamber, wherein the control unit is arranged in a predetermined portion of
the door unit.
In one aspect ofthe present invention, the door unit may include a door frame,
wherein the door frame defines an exterior shape of the door, and a door panel
arranged behind the door frame, wherein the control unit is arranged on the door
panel. An opening having an inner perimeter contact part extended in front and rear
directions may be provided in a predetermined portion of the door frame, wherein a
portion ofthe door panel may be exposed through the opening in the door frame. In
one aspect of the present invention, the door panel may further include a projection
provided within the opening, wherein the projection may couple the door panel to the
door fame.
In another aspect of the present invention, the projection on the door panel
includes an outer perimeter contact part that corresponds to the inner perimeter
contact part. For example, the inner perimeter contact part ofthe opening includes a
contact part that may contact the outer perimeter contact part. A stepped part may
be arranged behind the inner perimeter contact part to form a gap with the outer
perimeter contact part.
In yet another aspect of the present invention, the door panel may include a
protruding support part arranged behind the outer perimeter contact part, wherein the
protruding support part may support a rear end of the stepped part of the door frame.
The door panel may further include at least one joining rib, wherein the inner
perimeter contact part may be inserted between the outer perimeter contact part and
the joining rib.
In one aspect of the present invention, the door panel may include a seat,
wherein the control unit may be arranged on the seat, a display portion for displaying
information, and a back surface. An operation panel, provided with a plurality of
buttons allowing a user to operate the microwave oven, may be supported by a front
surface of the seat. A substrate, provided with a plurality of components enabling
operation of the plurality of buttons and the display portion, may be supported on the
back surface ofthe seat.
In one aspect of the present invention, the control unit may be electrically
connected to a device chamber of a microwave via a connection cable included
within the door of the microwave oven. Accordingly, the connection cable may
connect the control unit to the device chamber via a lower portion of the door unit
and a portion of a base plate of the microwave oven. The door may still further
include a cover for covering a portion of the connection cable between door unit and
the base plate, wherein the cover may have a height lower than a height of a leg
arranged on the base plate.
In one aspect of the present invention, the cover may include a reception
space and a door approach portion, wherein the reception space includes one opened
side for receiving the connection cable and the door approach portion extends to one
side of the reception space, thereby allowing the connection cable to pass through the
door approach portion. In one aspect of the present invention, the door approach
portion has a rounded exterior shape to prevent interference when the door is being
rotated. In another aspect of the present invention, at least one holding rib may be
provided in the reception space, wherein the holding rib secures the connection cable.
Thus, the foregoing door for a microwave oven of the present invention
permits more effective use of a space of the microwave oven, and prevent wrong
operation ofthe microwave oven.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 illustrates a perspective view of a related art microwave oven;
Figure 2 illustrates an exploded perspective view ofthe controller in Figure 1 ;
Figure 3 illustrates a perspective view of a microwave oven in accordance
with an embodiment ofthe present invention;
Figure 4 illustrates an exploded perspective view of the microwave oven
shown in Figure 3;
Figure 5 illustrates an exploded perspective view of the door shown in Figure
Figure 6 illustrates an exploded perspective view of a portion of a microwave
oven in accordance with another embodiment ofthe present invention;
Figure 7 illustrates a perspective view of microwave oven shown in Figure 6;
Figure 8 illustrates an exploded perspective view of a door of a microwave
oven in accordance with another embodiment ofthe present invention;
Figure 9 illustrates a section view taken across a line I-I as shown in Figure 8;
Figure 10 illustrates a section view corresponding to one in Figure 9, showing
a variation;
Figure 11 illustrates a perspective partial cut-away view of a door of a
microwave oven in accordance with another embodiment of the present invention;
and
Figure 12 illustrates a perspective partial cut-away view of a door of a
microwave oven in accordance with another embodiment ofthe present invention.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
Figure 3 illustrates a perspective view of a microwave oven in accordance
with an embodiment of the present invention. Figure 4 illustrates an exploded
perspective view ofthe microwave oven shown in Figure 3.
Referring to Figures 3 and 4, a cooking chamber 32 is arranged within a
cavity assembly 30 serving as a frame of the microwave oven and an electrical device
chamber 31 is arranged adjacent the cooking chamber 32. An object (e.g., food)
arranged within cooking chamber 32 may be heated by radiation (e.g., microwaves)
generated by various electrical devices arranged within the electrical device chamber
31. The various electrical devices may include, for example, a magnetron 12 for
generating microwaves, a high-voltage transformer 14 for supplying high voltage to
the magnetron 12, a fan 16 for generating an air flow inside the electrical device
chamber 31 thereby cooling the various electrical devices as they may become heated.
Further, a device substrate 31a may also be provided within the electrical device
chamber 31. A base plate 34 may be arranged at a bottom surface of the cavity
assembly 30. An outer case 33 may cover the cavity assembly 30 and the electrical
device chamber 31 , thereby forming outside top and side exterior surfaces of the
microwave oven.
Cooking chamber 32 may be opened or closed via door 50 attached to the
microwave oven via hinge plate 30a. The cooking chamber 32 may be closed when
door 50 contacts a front surface of the cavity assembly 30. A user may open or
close the cooking chamber 32 using a door handle 52 provided on the door 50. The
door may also include a control unit and a door unit, wherein the control unit
transmits signals capable of operating the microwave oven (e.g., to produce
microwaves at a predetermined power level for a predetermined amount of time) and
displays the operational status ofthe microwave oven.
Referring to Figures 3, 4 and 5, the door unit may, for example, include a door
frame 53 forming the exterior surface of the door 50, and a door panel 55 arranged
behind the door frame 53. In one aspect of the present invention, the control unit 60
may be provided on the door 50 via door panel 55.
An opening may be formed in an upper central portion of the door frame 53,
through which a portion of the door panel 55 may project and thus be exposed. In
one aspect ofthe present invention, the door panel 55 may be formed of a transparent
material (e.g., transparent plastic) to enable a user to view the interior of the cooking
chamber 32 from outside the microwave oven.
The control unit 60 may be provided at a predetermined position (e.g., an
upper portion) on the door panel 55 and include an operation panel 62 and a substrate
65. The operation panel 62 may, for example, include a display portion 63, a
plurality of buttons 62a enabling a user to operate the microwave oven, and a flexible
cable 64 for transmitting signals between the buttons 62a and a plurality of
components supported by substrate 65. Substrate 65 may, for example, support a
display 66 for displaying information within the display portion 63, connectors 67 for
electrically connecting to the flexible cable 64, and a connection cable 68 for
electrically connecting the control unit 60 to the components in the electrical device
chamber 31.
Control unit 60 may be seated on the door panel 55 via a seat 56. Seat 56
may be laterally arranged in, and project outwardly from, an upper portion ofthe door
panel 55. A display portion pass-through hole 56h may be centrally arranged within
seat 56 and a cable slot 56s may be arranged at a side portion of seat 56.
The operation panel 62 may be arranged on a front surface of seat 56, while
the substrate 65 may be arranged on a rear surface of the seat 56. Once arranged on
the seat 56, the location of the display portion 63 on the operation panel 62
corresponds to the location of the display portion pass-through hole 56h and the
flexible cable 64 may extend through the cable slot 56s toward the back of the door
panel 55 and connect to the connector 67 of substrate 65. Once assembled,
information generated by display 66 may be shown through display part 63 and
operation signals may be transmitted between the operation panel 62 and the substrate
65 via flexible cable 64 and connector 67.
According to the principles of the present invention, since control unit 60 may
be arranged on the door 50, space located in a front portion of the electrical device
chamber may be used for purposes generally not recognized by microwave ovens
such as those illustrated in Figures 1 and 2. For example, devices other than those
used in the heating of objects with microwaves may be provided within the front
portion of the electrical device chamber. Devices such as toasters, coffee makers,
and the like, may be incorporated into the microwave oven of the present invention
without increasing the size of the microwave oven. In one example shown in
Figures 3 and 4, a toaster 40 may be arranged at the front portion of the electrical
device chamber 31. Accordingly, a toaster body 49 may be arranged within the
electrical device chamber 31 and a toaster door 48, for selective opening/closing the
toaster 40, may be arranged at a front portion ofthe toaster body 49.
In order to operate the microwave oven according to the principles of the
present invention, a user must, for example, press button 63a on the operation panel
62. In pressing button 63a, the user is required to apply a force to the operation
panel 62. If the door 50 is opened, however, it is difficult to apply a force sufficient
to press button 63 a and therefore operate the microwave oven. Button 63 a, however,
may only be pressed with sufficient force when the door 50 is closed. Accordingly,
the principles of the present invention may prevent the microwave oven from being
operated when the door 50 is opened, either through the user or through a malfunction
of a sensing device.
As mentioned above, connection cable 68 is located between and electrically
connects, the control unit 60 and various electrical devices within the electrical device
chamber 31. In the present invention, connection cable 68 may be guided along a
coupling part of the door 50 and the body of the microwave oven, exposed at a lower
part of the microwave oven, and inserted into the base plate 34. Accordingly, a
portion of the connection cable 68 may be exposed to the outside at a location
between the door 50 and the body of the microwave oven. Being exposed, the
connection cable 68 may be vulnerable to damage (e.g., breakage).
With reference now to Figures 4, 6 and 7, the connection cable 68 may
electrically connect the substrate 65 of the control unit 60 to substrate 31a, or other
various electrical devices, within the electrical device chamber 31 or microwave oven
in such a way as to minimize damage it could potentially incur.
In one aspect of the present invention, connection cable 68 may be guided
from the substrate 65, through a cut-away portion 50a formed in a bottom surface of
the door 50, through a pass-through hole 34s formed in base plate 34, and into the
body of the microwave oven. According to the present invention, pass-through hole
34s may be arranged within a side portion of base plate 34 at the same side of the
microwave oven as hinge plate 30a. The connection cable 68 may be arranged
within the body of the microwave oven in a space defined between the outer case 33
and the cavity assembly 30.
The portion of the connection cable 68 that is exposed between the cut away
part 50a in the door 50 and the pass through hole 34s in the base plate 34 may be
covered with cover 70. In one aspect of the present invention, cover 70 may be
hexahedral. In another aspect of the present invention, cover 70 may include a side
arranged opposite the bottom of the base plate 34 is open such that cover 70 forms a
reception space 71 capable of receiving the connection cable 68. Additionally,
reception space 71 may include at least one holding rib 77 for holding the connecting
cable 68. In one aspect of the present invention, holding rib 77 may exhibit a ' ]'
form, substantially. In another aspect ofthe present invention, holding ribs 77 may be
formed such that fore ends of the holding ribs are alternately extended in opposite
directions.
In one aspect of the present invention, a door approach portion 73, extending
toward door 50, is provided at one end of cover 70 located at the cut-away part 50a at
the bottom of door 50. In another aspect of the present invention, the cut-away part
50a and the door approach portion 73 are rounded so as to minimize the degree to
which the two components interfere with each other when the door 50 is opened and
closed.
The door approach portion 73 includes a fore end having a connection cable
lead-out opening 74. The connection cable lead-out opening 74 has an opened side
formed to be in communication with an interior space of the door 50 at the cut-away
part 50a.
The cover 70 includes a fastening rib 75 formed so as to project into the
reception space 71 and be recessed in an exterior surface of the cover 70. Cover 70
may be secured to the base plate 34 by fastening a screw 76 to a fastening hole 34h in
the base plate 34 through a fastening hole 75a arranged within fastening rib 75.
Legs 60 may be arranged at the bottom surface of, and coupled to, the base
plate 34 to form a gap between the microwave oven and the surface on which the
microwave oven is arranged. In one aspect of the present invention, the height of
the gap between the microwave oven and the surface may be greater that the height of
cover 70.
According to the principles of the present invention, the portion of the
connection cable 68 located between door 50 and base plate 34 may be concealed by
the cover 70. Thus, any damage that may be incurred by the portion ofthe connection
cable 68 located between the door 50 and the body of the microwave oven may be
minimized.
Referring now to Figures 8 and 9, door 50 according to one embodiment of
the microwave oven ofthe present invention will now be explained.
As described above, the door 50 may include a door frame 53 and a door
• panel 55. A metallic frame part 16 forms a frame support structure for the entire door
50. A choke structure 16a may be provided at a rear edge of the metallic frame part
16 to prevent leakage microwaves generated within the cooking chamber 32. A cover
18 may be provided adjacent a rear edge of the choke structure 16a.
According to one aspect of the present invention, an opening 53a, defined by
an inner perimeter contact part 53b extended in front and rear directions, may be
formed in an upper central portion of the door frame 53, wherein the door panel 55 is
coupled to rear of the opening 53a. A projected part 55a, defined by an outer
perimeter contact part 55b, may be formed in door panel 55, wherein the projected
part 55a may be inserted into the opening 53a ofthe door frame 53.
When the projected part 55a of the door panel 55 is inserted into the opening
53a, the inner perimeter contact part 53b and the outer perimeter contact part 55b are
brought into contact.
Referring now to Figures 10 and 11, door 50 according to another
embodiment of the microwave oven ofthe present invention will now be explained.
According to the present embodiment of the invention, the door frame 53 and
the door panel 55 may be provided substantially as described with reference to
Figures 8 and 9, however, the portions ofthe door frame 53 and ofthe door panel 55
that contact each other differ.
For example, while door panel 55 includes a projected part 55a, defined by the
outer perimeter part 55b, to be inserted in the opening 53a of the door frame 53, door
panel 55 further includes a support part 55c arranged behind the outer perimeter
contact part 55b and extended in radial directions.
Additionally, while door frame 53 includes an opening 53a defined by the
inner perimeter contact part 53b, the door frame 53 further includes a contact part 531,
provided so as to contact the outer perimeter contact part 55b, and a stepped part 533,
provided so as not to contact the door panel 55. In one aspect of the present
embodiment, contact part 531 has a first length, LI, that is shorter than a second
length, L2, ofthe stepped part 533.
Accordingly, when the projected part 55a of the door panel 55 is inserted into
the opening 53a, the contact part 531 of he inner perimeter contact part 53b contacts,
and is inserted into, the outer perimeter contact part 55b while the stepped part 533
does not contact the outer perimeter contact part 55b to form a gap therebetween. In
one aspect of the present invention, a rear end 535 of the inner perimeter contact part
53a contacts the support part 55c of the door panel 55. Accordingly, the rear end
535 contacts the support part 55c and facilitates the door panel 55 to contact the door
frame 53.
According to the present embodiment, in assembling the door frame 53 with
the door panel 55, the first length, LI, of contact is shorter than the second length, L2,
of no contact. Accordingly, the door frame 53 and the door panel 55 may be
assembled after they come into contact over a comparatively short length, LI.
According to the present invention, the inner perimeter contact part 53b of the
door frame and the outer perimeter contact part 55b of the door panel may be brought
into contact in over a first length, LI . Therefore, assembly of the door frame 53 and
the door panel 55 is simple, and any noise caused by contact between the two
components after they are assembled may be reduced. Moreover, even if contact
area between the two components is reduced, the contact ofthe rear end 535 with the
support part 55c may provide a robust door assembly as the rear end 535 and the
support part 55c make close contact even in an assembly state.
Referring now to Figure 12, door 50 according to yet another embodiment of
the microwave oven ofthe present invention will now be explained.
According to the present embodiment of the invention, the door frame 53 and
the door panel 55 may be provided substantially as described with reference to
Figures 10 and 11, however, the present embodiment additionally includes a joining
rib 90 for coupling of the door frame 53 to the door panel 55.
Accordingly, the door panel 55 includes a joining rib 90 projected forward
from an outer surface of the support part 55c. The joining rib 90 extends forward
from the outside outer perimeter surface 55d and backward from the support part 55c
such that a gap is provided from the joining rib 90 to the outer perimeter contact part
55b. In one aspect of the present embodiment, a plurality of the joining parts 90
may be provided at predetermined intervals along the entire outer perimeter surface
of the projected part 55a.
The door assembly of the present embodiment facilitates insertion of the inner
perimeter contact part 53b between the joining ribs 90 and the outer perimeter contact
part 55b. For example, when the door panel 55 is joined to the rear of the door
frame 53, the inner perimeter contact part 53b is inserted between the outer perimeter
contact part 55b and the joining ribs 90. Moreover, if a plurality of the joining ribs
90 are formed on an outer perimeter surface of the projected part 55a, the inner
perimeter contact part 53b may be inserted between the joining ribs 90 and the outer
perimeter contact part 55b.
According to the present invention, if an external force is applied to the door
frame 53 or the door panel 55 after the two components are coupled together, the
assembly of the door frame and door panel may be maintained. Moreover, the
secure coupling of the door frame 53 and the door panel 55 prevents deformation of
the door frame 53 or the door panel 55 due to heat generated inside the cooking
chamber 32 and relative movement between the door frame 53 and door panel 55.