DESCRIPTION
COOKING DEVICE AND HEATING DEVICE PROVIDED WITH THE
SAME
TECHNICAL FIELD
The present invention relates to a cooking device for use in a
heating device, and more particularly to a grill pan for cooking food by
making use of the heat generated by irradiation of microwaves.
BACKGROUND ART
In recent years, high-frequency heating devices, such as a
microwave oven, have had a cooking function using a cooking device, i.e. a
so-called grill pan, disposed in the high-frequency heating device, in
addition to a microwave heating function for heating food by radiating
microwaves directly to the food. Hereinafter, the former function is
referred to as a grill pan cooking function.
This grill pan cooking is the following cooking method. A cooking
pan has a heating element applied to the back surface for generating heat
by absorbing microwaves. The cooking pan is disposed in a heating
chamber, and food is placed on the cooking pan. The heat generated from
the heating element by irradiation of microwaves cooks the food. For
such grill pan cooking, when the food is cooked by the contact with the
grill pan that generates heat with the microwaves, grease oozes from the
food, which needs to be discharged from between the food and the grill
pan. Hereinafter, this action is referred to as degreasing.
Conventionally, a grill pan configured as shown in Figs. 5 through 7

is available for degreasing (see Patent Literature 1, for example). The
above conventional technique is described with reference to the
accompanying drawings. Figs. 5 through 7 show a top view, a side
sectional view, and a perspective view of the conventional grill pan,
respectively. As shown in Figs. 5 through 7, conventional grill pan 101
has an overall substantially rectangular shape as viewed from the top.
Edge 102 in a flange shape is formed on the periphery of grill pan 101.
Peripheral channel 103 is formed inside edge 102.
A plurality of banks 111, each in the shape of an elongate, thin,
rectangular parallelepiped having rounded corners, is arranged inside
peripheral channel 103. Between two banks adjacent to each other,
groove 130 is formed. Each bank has a length equal to that from one side
to the opposed side of peripheral channel 103. Thus, the inside part of
peripheral channel 103 has a corrugated shape where banks and grooves
are arranged alternately. The bottom of peripheral channel 103 is lower
than the bottom of groove 130.
Hereinafter, only banks 111 and 121 and groove 130 are focused.
Here, the lengthwise direction of the banks is defined as a longitudinal
direction; the direction perpendicular to the lengthwise direction of the
banks is defined as a lateral direction.
The top surfaces of banks 111 and 121 have respective placement
surfaces 112 and 122 each in a substantially planar shape on which food is
to be placed. Heating element 104, i.e. an electromagnetic wave
absorption material predominantly composed of ferrite, is applied to the
back surfaces of banks 111 and 121, and groove 130.
When grill pan 101 configured as above is disposed in the heating
chamber of a high-frequency heating device and microwaves are radiated

to the back surface of grill pan 101, heating element 104 generates heat
and the heat conducted from placement surfaces 112 and 122 can cook the
food. For conventional grill pan 101, the grease oozing from the food in
cooking passes through groove 130 and accumulates in peripheral channel
103. Here, in order to improve cooking efficiency and uneven roasting, it
is preferable to sufficiently increase the lateral length, i.e. the lateral
width, of each placement surface so as to reduce the space between
adjacent two banks, i.e. the lateral width of the groove, to some extent
(see Patent Literature 2, for example).
Typically, a grill pan is formed by pressing a metal plate. For this
reason, if the groove is formed deeper (e.g. with a depth of 5 mm) for
efficient degreasing, the lateral width of the groove needs to be increased.
As a result, the area of the placement surfaces to be in contact with food is
decreased. Thus, in the case where food needs to be cooked with a
sufficient roast color, part of the food on the groove is heated insufficiently
and this makes it difficult to give a desired roast color to the food.
Conversely, if the lateral width of the groove is formed smaller, the
groove is shallower. Thus, soft food falls in the groove and makes contact
with the groove. At this time, if the food contains much fat, the grease
oozing from the food in cooking is accumulated between the food and the
groove by surface tension and inhibits heat conduction. Thus, a desired
roast color cannot be given to the food.
In other words, the conventional grill pan cannot address the
following two problems at the same time: giving a desired roast color to
the food; and efficient degreasing. The present invention addresses the
above two problems at the same time. The present invention provides a
grill pan that has larger placement surfaces to be in contact with food and

performs efficient degreasing, and enhances the performance of grill pan
cooking in a high-frequency heating device.
[Citation List]
[Patent Literature]
[PTL1]
Japanese Patent Unexamined Publication No. 2007-225186
[PTL2]
Japanese Patent Unexamined Publication No. 2006-52932
SUMMARY OF THE INVENTION
In order to address the above problems, a cooking device of the
present invention is a cooking device for cooking food placed thereon, and
includes the following elements:
a plurality of banks arranged in the lateral direction, each of the
banks having a placement surface for supporting the food being placed;
and
a groove formed between the plurality of banks.
In each of the plurality of banks, the lateral width of the placement
surface varies depending on positions along the longitudinal direction of
the bank.
The depth of the groove varies depending on positions along the
longitudinal direction of the groove. Further, the depth of the groove in
proximity to a portion of each placement surface having a larger lateral
width is shallower than the depth of the groove in proximity to a portion
of the placement surface having a smaller lateral width.
The cooking device of the present invention can provide a grill pan
that has larger placement surfaces to be in contact with the food and

performs efficient degreasing, and enhance the performance of grill pan
cooking in a high-frequency heating device.
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 is a top view of a cooking device in accordance with a first
exemplary embodiment of the present invention.
Fig. 2A is a side sectional view of the cooking device in accordance
with the first exemplary embodiment.
Fig. 2B is a side sectional view of the cooking device in accordance
with the first exemplary embodiment.
Fig. 3 is a perspective view of the cooking device in accordance with
the first exemplary embodiment.
Fig. 4 is a general view of a heating device including the cooking
device in accordance with the first exemplary embodiment.
Fig. 5 is a top view of a conventional cooking device.
Fig. 6 is a side sectional view of the conventional cooking device.
Fig. 7 is a perspective view of the conventional cooking device.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
A first aspect in accordance with the present invention provides a
cooking device for cooking food placed thereon includes the following
elements:
a plurality of banks arranged in the lateral direction, each of
the banks having a placement surface for supporting the food being
placed; and
a groove formed between the plurality of banks.
In each of the plurality of banks, the lateral width of the placement

surface varies depending on positions along the longitudinal direction of
the bank.
The depth of the groove varies depending on positions along the
longitudinal direction of the groove. Further, the depth of the groove in
proximity to a portion of each placement surface having a larger lateral
width is shallower than the depth of the groove in proximity to a portion
of the placement surface having a smaller lateral width.
In accordance with the first aspect of the present invention,
enlarging the portion of each placement surface highly likely to be in
contact with the food allows more heat to be conducted to the food from
the placement surface.
Forming a slope in the groove allows the grease oozing from the
food to be discharged easily. Further, the portion of each placement
surface highly likely to be in contact with the food is enlarged and a slope
is formed in the groove. This allows more heat to be conducted to the
food from the placement surface, and the grease oozing from the food to be
discharged easily.
A second aspect in accordance with the present invention provides a
cooking device of the first aspect of the present invention, wherein the
lateral width of the placement surface is largest in the vicinity of the
longitudinal center of each of the plurality of banks. In accordance with
the second aspect of the present invention, enlarging the portion of each
placement surface highly likely to be in contact with the food allows more
heat to be conducted to the food from the placement surface.
A fourth aspect in accordance with the present invention
provides a cooking device of the first aspect of the present invention,
wherein the depth of the groove in proximity to a portion of each

placement surface having a larger lateral width is shallower than the
depth of the groove in proximity to a portion of the placement surface
having a smaller lateral width. In accordance with the fourth aspect of
the present invention, the portion of each placement surface highly likely
to be in contact with the food is enlarged and a slope is formed in the
groove. This allows more heat to be conducted to the food from the
placement surface, and the grease oozing from the food to be discharged
easily.
A sixth aspect in accordance with the present invention
provides a cooking device of the first aspect of the present invention,
wherein the lateral width of the placement surface is largest in the
vicinity of the longitudinal center of each of the plurality of banks and the
depth of the groove is shallowest in proximity to the longitudinal centers
of the plurality of banks. In accordance with the sixth aspect of the
present invention, the portion of each placement surface highly likely to
be in contact with the food is enlarged and a slope is formed in the groove.
This allows more heat to be conducted to the food from the placement
surface, and the grease oozing from the food to be discharged easily.
A seventh aspect in accordance with the present invention provides
a heating device including a heating chamber, wherein the cooking device
of the first aspect of the present invention is included therein. In
accordance with the seventh aspect of the present invention, the
performance of grill pan cooking in the heating device can be enhanced.
Hereinafter, a cooking device in accordance with the preferred
embodiment of the present invention is detailed with reference to the
accompanying drawings.

FIRST EXEMPLARY EMBODIMENT
Figs. 1 through 3 are a top view, a side sectional view, and a
perspective view, respectively, of a grill pan in accordance with the first
exemplary embodiment of the present invention. More specifically, Fig.
2A is a sectional view of the grill pan as viewed from the longitudinal
direction; Fig. 2B is a sectional view of the grill pan as viewed from the
lateral direction.
As shown in Figs. 1 through 3, the grill pan of this exemplary
embodiment has an overall substantially rectangular shape as viewed
from the top. Edge 2 in a flange shape is formed on the periphery of the
grill pan. Peripheral channel 3 is formed inside edge 2. A plurality of
banks, each in the shape of an elongate, thin, rectangular parallelepiped
having rounded corners, is arranged in the lateral direction inside
peripheral channel 3. Between two banks adjacent to each other, a
groove is formed. Each bank has a length equal to that from one side to
the opposed side of peripheral channel 3. Thus, the inside part of
peripheral channel 3 has a corrugated shape where banks and grooves are
arranged alternately in the lateral direction. The bottom of peripheral
channel 3 is lower than the bottom of groove 30.
Hereinafter, only banks 11 and 21 and groove 30 are focused. The
top surfaces of banks 11 and 21 have respective placement surfaces 12 and
22 each in a substantially planar shape on which food is to be placed.
Heating element 4, i.e. an electromagnetic wave absorption material
predominantly composed of ferrite, is applied to the back surfaces of
banks 11 and 21, and groove 30.
Fig. 4 is a general view of a heating device including the grill pan in
accordance with the first exemplary embodiment of the present invention.

In this exemplary embodiment, as the heating device, a high-frequency
heating device is described. As shown in Fig. 4, heating device 50
includes the following elements: heating chamber 51 for housing food;
door 52 for blocking the front opening of heating chamber 51; a magnetron
(not shown) for generating microwaves. Rails 53 are disposed on the
right and left sidewalls of the interior of heating chamber 51. Edge 2 of
grill pan 1 is placed on rails 53, so that grill pan 1 is disposed in a
predetermined position inside heating chamber 51.
When grill pan 1 configured as above is disposed in the
predetermined position inside heating chamber 51 and the back surface of
grill pan 1 is irradiated with microwaves, heating element 4 generates
heat and the heat conducted from placement surfaces 12 and 22 can cook
the food. In grill pan 1 of this exemplary embodiment, the grease oozing
from the food in cooking passes through groove 30 and accumulates in
peripheral channel 3.
The operation having been described above is the same as that of
the conventional grill pan. Hereinafter, the features of the grill pan of
this exemplary embodiment are described. As shown in Fig. 1, the
lateral widths of placement surfaces 12 and 22 on the top surfaces of
banks 11 and 21 are largest in the vicinity of the longitudinal centers of
banks 11 and 21, respectively, and are decreased toward the proximity to
peripheral channel 3.
As shown in Fig. 2B, the distances between the bottom of groove 30
and placement surfaces 12 and 22 in the vertical direction, i.e. depth D of
groove 30, are smallest in proximity to the vicinity of the longitudinal
centers of respective banks 11 and 21, and are increased toward the
proximity to peripheral channel 3. In other words, since placement

surfaces 12 and 22 are each in a substantially planar shape, the bottom of
groove 30 is highest in the vicinity of the longitudinal centers of banks 11
and 21 and is lowered toward the proximity to peripheral channel 3.
These features can provide the following advantages.
(1) Since the areas of placement surfaces 12 and 22 are larger in the
vicinity of the center of grill pan 1 where food is highly likely to be placed,
the contact area between the food and the placement surfaces can be
increased.
(2) The depth of groove 30 increases in the direction from the vicinity of
the center of grill pan 1 toward the proximity to peripheral channel 3.
That is, in the vicinity of the center of grill pan 1, soft food can fall in
groove 30 and make contact with the bottom of groove 30. in the positions
nearer to peripheral channel 3, the food is less likely to make contact with
the bottom of groove 30. Thus, the grease oozing out in cooking is led to
peripheral channel 3 along the slope of groove 30.
Therefore, this configuration can remove the grease that is
accumulated between the food and the grooves and inhibits heat
conduction, thereby giving a sufficient roast color even to fatty food.
(3) The depth of groove 30 is shallower in a portion having a smaller
lateral width and is greater in a portion having a larger lateral width.
Thus, grill pan 1 has a shape that allows easier cleaning than the
conventional shape.
(4) With the above features, the slopes of the side surfaces of banks 11 and
21 from placement surfaces 12 and 22 to groove 30 have a substantially
equal angle in every longitudinal portion of banks 11 and 21, respectively.
No particular portion has a slope steeper than those of the other portions
(see Fig. 3). Therefore, grill pan 1 of this exemplary embodiment can be

formed by pressing easily.
The following consideration is given to the more specific
configuration of grill pan 1 of this exemplary embodiment. Even when a
food container having a relatively small lateral width (e.g. a coffee cup) is
placed on the plurality of placement surfaces, the food container is always
placed on at least two placement surfaces so as not to fall. Assuming
that the average bottom diameter of such food containers is 48 mm, for
example, the lateral width of the largest portion of the placement surface
is set to 35 mm. It is also preferable to set depth D of groove 30 in the
shallowest portion to 1.5 mm, and the average gradient of placement
surfaces 12 and 22 from the longitudinal centers to 2° or greater.
Further, when dents 5 are formed at the four corners of the flange portion
on the periphery of edge 2 as shown in Figs. 1 and 3, the strength of grill
pan 1 can be enhanced and the grill pan reaching high temperatures after
cooking can be handled easily.
As described above, the cooking device of the present invention can
provide a grill pan that has larger placement surfaces to be in contact
with food and performs efficient degreasing, and enhance the performance
of grill pan cooking in a high-frequency heating device. In this
exemplary embodiment, placement surfaces 12 and 22 are substantially
planar. A slight slope may be formed from the vicinity of the center
toward groove 30 or peripheral channel 3 both in the longitudinal
direction and the lateral direction. The structure of the placement
surfaces is not limited to this exemplary embodiment.
In this exemplary embodiment, grill pan 1 is formed by pressing a
metal plate. However, the present invention is not limited to pressing.
For example, grill pan 1 can be cut out from a forged part. This allows

optional settings suitable for applications, such as the case where the
depth of the groove is constant and only the lateral width of each
placement surface is different depending on the longitudinal position of
the corresponding bank, and the case where the lateral width of each
placement surface is constant and only the depth of the groove is different
depending on the longitudinal position of the corresponding bank.
INDUSTRIAL APPLICABILITY
As detailed above, the cooking device of the present invention is
applicable to high-frequency heating devices, such as a microwave oven.
The cooking device of the present invention is also applicable to a cooking
pan in a corrugated shape that is disposed in a griller using heating
means other than high-frequency heating, such as a sheathed heater.
REFERENCE MARKS IN THE DRAWINGS
1 Grill pan
2 Edge
3 Peripheral channel
4 Heating element
5 Dent
11, 21 Bank
12 Placement surface
22 Placement surface
30 Groove

We claim :
1. A cooking device for cooking food placed thereon, the cooking
device comprising:
a plurality of banks arranged in a lateral direction, each of the
banks having a placement surface for supporting the food being placed.'
and
a groove formed between the plurality of banks,
wherein, in each of the plurality of banks, a lateral width of the
placement surface varies depending on positions along a longitudinal
direction of the bank,
a depth of the groove varies depending on positions along a
longitudinal direction of the grove, and
the depth of the groove in proximity to a portion of the placement
surface having a larger lateral width is shallower than the depth of the
groove in proximity to a portion of the placement surface having a smaller
lateral width.
2. The cooking device of claim 1, wherein the lateral width of the
placement surface is largest in a vicinity of a longitudinal center of each of
the plurality of banks.
3.The cooking device of claim 1, wherein the depth of the groove is
shallowest in proximity to the longitudinal center of the plurality of
banks.

4. The cooking device of claim 1, wherein the lateral width of the
placement surface is largest in a vicinity of a longitudinal center of each of
the plurality of banks and the depth of the groove is shallowest in
proximity to the vicinity of longitudinal centers of the plurality of banks.
5. A heating device, comprising a heating chamber, wherein the
cooking device of claim 1 is included in the heating chamber.

A cooking device for cooking food placed thereon includes the following
elements: a plurality of banks (11) and (21) arranged in the lateral direction
and having respective placement surfaces (12) and (22) for supporting the
food being placed; and a groove (30) formed between the plurality of banks
(11) and (21). In this cooking device, the lateral widths of the placement
surfaces (12) and (22) are largest in the vicinity of the longitudinal center of
the plurality of banks (11) and (21), respectively, and the depth of the groove
(30) is shallowest in proximity to the vicinity of the longitudinal center of the
plurality of banks (11) and (21).