Abstract:
A cooking apparatus and a method of controlling the cooking apparatus allow a temperature distribution of hot air to be uniform in a cooking cavity so that food in the cooking cavity is uniformly cooked, and enables initial heating of the air in the cooking cavity to be rapidly accomplished so that a cooking time is reduced. The cooking apparatus includes a cooking cavity, and first and second convection modules. The cooking cavity cooks food contained therein. The first convection module heats air in the cooking cavity and circulates the heated air. The second convection module is placed to be opposite to the first convection module so as to heat the air and circulate the heated air.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of Korean Patent Application No. 2003-89777, filed Dec. 10, 2003 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates, in general, to a cooking apparatus and, more particularly, to a cooking apparatus that includes a magnetron to generate microwaves and convection modules to supply hot air into a cooking cavity. 
   2. Description of the Related Art 
   A cooking apparatus disclosed in Japanese Unexamined Pat. Publication No. 8-247473 includes a body in which an inner casing forming a cooking cavity is placed inside an outer casing. An open front of the cooking cavity is selectively opened and closed by a door, and an air-blowing chamber is recessed behind the cooking cavity in the inner casing. A convection fan to compulsorily circulate air in the cooking cavity and a heater to heat the circulated air are placed in the air-blowing chamber. A cover is placed in front of the convection fan and the heater, that is, in front of the air-blowing chamber. 
   However, since the conventional cooking apparatus has a structure, in which hot air which is discharged through a hot air outlet formed at a back of the cooking cavity, is blown onto food placed on a food rack in the cooking cavity, and the hot air concentrically heats a specific portion of the food, so that the specific portion of the food is overcooked or burned, and a portion of the food opposite to the specific portion is left uncooked, thus the food is not uniformly cooked. 
   SUMMARY OF THE INVENTION 
   Accordingly, an aspect of the present invention provides a cooking apparatus that allows a temperature distribution of hot air to be uniform in a cooking cavity. As a result, food in the cooking cavity is uniformly cooked. The present invention also enables initial heating of air in the cooking cavity to be rapidly accomplished so that a cooking time is reduced. 
   Additional and/or other aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
   The above and/or other aspects are achieved by providing a cooking apparatus, including a cooking cavity, and first and second convection modules. The cooking cavity cooks food contained therein. The first convection module heats air in the cooking cavity and then circulates the heated air. The second convection module is placed opposite to the first convection module to heat the air in the cooking cavity and then circulate the heated air. 
   The above and/or other aspects are achieved by providing a cooking apparatus, including a cooking cavity, and first and second convection modules. The cooking cavity cooks food contained therein. The first convection module heats air in the cooking cavity and circulates the heated air. The second convection module is opposite to the first convection module and is vertically offset from the first convection module to heat the air and then circulate the heated air. 
   The above and/or other aspects are achieved by providing a cooking apparatus, including a cooking cavity, and first and second convection modules. The cooking cavity cooks food contained therein. The first convection module heats air in the cooking cavity and circulates the heated air. The second convection module is opposite to the first convection module and is horizontally offset from the first convection module so as to heat the air and then circulate the heated air. 
   The above and/or other aspects are achieved by providing a method of controlling a cooking apparatus, including heating air in a cooking cavity and circulating the heated air using first and second convection modules in a convection-cooking mode, and stopping the first and second convection modules if a predetermined first cooking time has elapsed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, of which: 
       FIGS. 1 to 3  are views showing constructions of cooking apparatuses, according to embodiments of the present invention; 
       FIG. 4  is a block diagram showing a control system of a cooking apparatus of the present invention; and 
       FIGS. 5 to 7  are flowcharts showing methods of controlling the cooking apparatus, according to embodiments of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. 
   Cooking apparatuses and methods of controlling the cooking apparatuses according to embodiments of the present invention are described with reference to  FIGS. 1 to 6  below.  FIGS. 1 to 3  are cross sections showing constructions of convection microwave ovens according to embodiments of the present invention.  FIG. 1  is a cross section showing a convection microwave oven  100  of the present invention, in which first and second convection modules  102  and  104  located on both sides of a cooking cavity  114 , respectively, to be opposite to each other. 
   As shown in  FIG. 1 , the first convection module  102  includes a first convection fan  102   a , a first fan motor  102   c  to operate the first convection fan  102   a , and a first heater  102   b  to heat circulated air. The first convection fan  102   a  is a centrifugal fan, so that, when the first convection fan  102   a  rotates, air in the cooking cavity  114  is drawn through a center portion of the convection fan  102   a  and air heated by the first heater  102   b  is discharged through an outer portion of the convection fan  102   a . A first cover member  106  is provided between the first convection module  102  and the cooking cavity  114 . An air inlet  106   a  is formed along a center portion of the first cover member  106  to draw air from the cooking cavity  114 , and a hot air outlet  106   b  is formed along an outer portion of the first cover member  106  to discharge hot air. 
   Accordingly, when the first convection module  102  is operated, air is drawn from the cooking cavity  114  to the center portion of the first convection fan  102   a , heated by the first heater  102   b , and then supplied back into the cooking cavity  114  through the outer portion of the first convection fan  102   a . In other words convection of the hot air, in which the air is drawn into the center portion of the first cover member  106  and the hot air is discharged from the outer portion of the first cover member  106 , as indicated by arrows in a left side of  FIG. 1 , is performed. 
   The second convection module  104  includes a second convection fan  104   a , a second fan motor  104   c  to operate the second convection fan  104   a , and a second heater  104   b  to heat circulated air. The second convection fan  104   a  is an axial-flow fan, so that, when the second convection fan  104   a  rotates, air in the cooking cavity  114  is drawn through an outer portion of the second convection fan  104   a , and air heated by the heater  104   b  is discharged through a center portion of the second convection fan  104   a . That is, the first and second convection fans  102   a  and  104   a  have opposite draw and discharge directions. A second cover member  108  is provided between the second convection module  104  and the cooking cavity  114 . An air inlet  108   b  is formed along an outer portion of the second cover member  108  to draw the air from the cooking cavity  114 , and a hot air outlet  108   a  is formed along a center portion of the second cover member  108  to discharge heated air. 
   Accordingly, when the second convection module  104  is operated, the air in the cooking cavity  114  is drawn through an outer portion of the second convection fan  104   a , heated by the heater  104   b , and then supplied back into the cooking cavity  114  through a center portion of the second convection fan  104   a . Convection of the hot air, in which the air is drawn into the outer portion of the second cover member  108  and the hot air is discharged from the center portion of the second cover member  108 , as indicated by arrows in a left side of  FIG. 1 , is performed. 
   If the first and second convection modules  102  and  104  are both operated, the first convection module  102  draws air from a center part of the cooking cavity  114 , heats the air, and then discharges the heated air to front, back, upper, and lower parts of the cooking cavity  114 . The second convection module  104  draws in the heated air, which was discharged into the outer parts of the cooking cavity  114 , heats the drawn air again, and then discharges the heated air to the center part of the cooking cavity  114 . 
   Similarly, heated air, which was discharged from the second convection module  104  into the center part of the cooking cavity  114 , is drawn back into the first convection module by the first convection module  102 . The redrawn air is reheated and then discharged. Supplementary draws and discharges of the first and second convection modules  102  and  104  allow the convection of the hot air to be effectively performed all through the cooking cavity  114 , to distribute temperature uniformly throughout the cooking cavity  114 . As a result, hot air with a uniform temperature distribution is applied to the entire food, thereby uniformly cooking the entire food. 
     FIG. 2  is a cross section showing a convection microwave oven  200 , according to another embodiment of the present invention, which shows a cross section of the convection microwave oven  200  in which first and second convection modules  202  and  204  are provided on both sides of a cooking cavity  214  at, respectively, different heights. As shown in  FIG. 2 , the first convection module  202  includes a first convection fan  202   a , a first fan motor  202   c  to operate the first convection fan  202   a  and a first heater  202   b  to heat circulated air. The first convection module  202  is provided on a lower part of a first side of the cooking cavity  214 . The first convection fan  202   a  is a centrifugal fan, so that, when the first convection fan  202   a  rotates, a center portion of the first convection fan  202   a  draws air from the cooking cavity  214 , and an outer portion of the cooking cavity  214  discharges air heated by the first heater  202   b . A first cover member  206  is provided between the first convection module  202  and the cooking cavity  214 . An air inlet  206   a  is formed in a center portion of the first cover member  206  to draw air, and a hot air outlet  206   b  is formed along an outer portion of the first cover member  206  to discharge the heated air. 
   Accordingly, when the first convection module  202  is operated, the air in the cooking cavity  214  is drawn through the center portion of the first convection fan  202   a , heated by the first heater  202   b , and then supplied back into the cooking cavity  214  through the outer portion of the first convection fan  202   a . In other words, convection of the hot air in which the air is drawn into the center portion of the first cover member  206  and the hot air is discharged from the outer portion of the first cover member  206 , as indicated by arrows in a left side of  FIG. 2 , is performed. 
   A second convection module  204  includes a second convection fan  204   b , a second fan motor  204   c  to operate the second convection fan  204   a , and a second heater  204   b  to heat circulated air. The second convection module  204  is provided on an upper part of a second side of the cooking cavity  214  to be opposite to the first convection module  202 . The second convection module  204  is placed on the second side of the cooking cavity  214  at a height higher than that of the first convection module  202 . The height of the second convection module  204  is such that a height of a lower part of the second hot air outlet  208   b  of a second cover member  208  is similar to that of the first air inlet  206   a  formed in a center portion of the first cover member  206 . The second convection fan  204   a  is also a centrifugal fan, so that, when the second convection fan  204   a  rotates, air in the cooking cavity  214  is drawn through a center portion of the second convection fan  204   a , and the air heated by the second heater  204  is discharged through an outer portion of the second convection fan  204   a . That is, the first and second convection fans  202   a  and  204   a  have opposite draw and discharge directions. The second cover member  208  is provided between the second convection module  204  and the cooking cavity  214 . An air inlet  208   a  is formed along a center portion of the second cover member  208  to draw air in the cooking cavity  214 , and a hot air outlet  208   b  is formed along an outer portion of the second cover member  208  to discharge the heated air. 
   Accordingly, when the second convection module  204  is operated, the air in the cooking cavity  214  is drawn through the center portion of the second convection fan  204   a , heated by the second heater  204   b , and then directed back into the cooking cavity  214  through the outer portion of the second convection fan  204   a . As a result, convection of the hot air, in which the air is drawn into the center portion of the second cover member  208  and the hot air is discharged from the outer portion of the second cover member  208 , as indicated by arrows in a right side of  FIG. 2 , is performed. 
   If the first and second convection modules  202  and  204  are operated simultaneously, the first convection module  202  draws air from the cooking cavity  214 , heats the air, and discharges the heated air into an upper half of the cooking cavity  214 . As with the first convection module  202 , the second convection module  204  draws air through the center portion of the second convection module  204  and discharges hot air through the outer portion of the second convection module  204  Therefore, the second convection module  204  draws air into the second convection module, heats the drawn air, and then discharges the heated air into a lower half of the cooking cavity  214 . Although the first and second convection modules  202  and  204  draw and discharge air in opposite directions, a lower part of the second hot air outlet  208   b  of the second convection module  204  and the first air inlet  206   a  formed in the center portion of the second cover member  206  are located at equal heights. Thus, the second convection module  204  draws hot air, which was discharged back into the cooking cavity  214 , through the first convection module  202 , reheats the drawn air, and then discharges the heated air. 
   As described above, the first and second convection modules  202  and  204  are located at different heights, but the air inlets and hot air outlets of the first and second convection modules  202  and  204  are partially overlapped. Accordingly, convection of the hot air in the cooking cavity  214  is effectively performed, and a temperature distribution in the cooking cavity  214  is made uniform. As a result, hot air with a uniform temperature distribution is applied to the entire food in the cooking cavity  214 , so that entire food is uniformly cooked. 
     FIG. 3  is a transverse section showing a convection microwave oven  300 , according to still another embodiment of the present invention, in which first and second convection modules  302  and  304  are provided on both sides of a cooking cavity  314 , respectively, at substantially similar heights. However, the first convection module  302  is provided on a front portion of a first side of the cooking cavity  314 , and the second convection module  304  is provided on a back portion of a second side of the cooking cavity  314 . That is, locations of an air inlet  306   a  and a hot air outlet  306   b  of the first convection module  302  are offset from locations of an air inlet  308   a  and a hot air outlet  308   b  of the second convection module  304 . However, the air inlet and the hot air outlet  306   a  and  306   b  are partially overlapped, so that convection of the hot air in the cooking cavity  314  is effectively performed and a temperature distribution in the cooking cavity  314  is made uniform. As a result, the hot air with a uniform temperature distribution is applied to entire food in the cooking cavity  314  uniformly cook the entire food. 
     FIG. 4  is a block diagram showing a control system of a convection microwave oven  100 , according to an embodiment of the present invention. As shown in  FIG. 4 , an input  404 , to input a cooking mode or a set value for cooking, is connected to an input terminal of a controller to control an overall operation of the convection microwave oven  100 . A magnetron driver  406 , a tray motor driver  408 , and first and second convection module drivers  410  and  412  are connected to an output terminal of the controller  402  to operate a magnetron  110 , a tray motor  112 , and first and second convection modules  102  and  104 , respectively. 
     FIGS. 5 to 7  are flowcharts showing methods of controlling a cooking apparatus, according to embodiments of the present invention. 
     FIG. 5  is a flowchart showing a method of controlling a convection-cooking mode using only the first and second convection modules  102  and  104 . As shown in  FIG. 5 , when a user selects the convection-cooking mode in operation  502 , the first and second convection modules  102  and  104  are operated simultaneously in operation  504 . Food is cooked by hot air generated by the first and second convection modules  102  and  104 . If a predetermined cooking time has elapsed in operation  506 , the first and second convection modules  102  and  104  are stopped. Thus, the convection-cooking mode ends in operation  508 . Since the first and second convection modules  102  and  104  are operated simultaneously, a smooth convection of hot air is performed in the cooking cavity  114 , and a temperature of the air is rapidly increased. 
     FIG. 6  is a flowchart showing a method of controlling a complex cooking mode using the first and second convection modules  102  and  104  and the magnetron  110 . As shown in  FIG. 6 , when a convection-cooking mode is selected by a user in operation  602 , the first and second convection modules  102  and  104  are all operated in operation  604 . Food is cooked by hot air generated by the first and second convection modules  102  and  104 . If a predetermined cooking time (that is, cooking time based on only convection) has elapsed in operation  606 , one (for example, the second convection module  104 ) of the first and second convection modules  102  and  104  is stopped in operation  608 . The magnetron  110  is operated while the first convection module  102  is continuously operated, so as to perform complex cooking using convection and microwaves in operation  610 . If a predetermined second cooking time to perform the complex cooking has elapsed in operation  612 , the first convection module  102  and the magnetron  110  are both stopped. Thus, the convection-cooking mode ends in operation  614 . 
     FIG. 7  is a flowchart showing a method of controlling a cooking mode using the first and second convection modules  102  and  104 , including alternately operating the first and second convection modules  102  and  104  rather than operating the first and second convection modules  102  and  104  simultaneously. As shown in  FIG. 7 , when a convection-cooking mode is selected by a user in operation  702 , the first and second convection modules  102  and  104  are alternately operated in operation  704 . That is, the first and second convection modules  102  and  104  are operated in an alternate manner. Food is cooked by hot air, which is generated by alternately operating the first and second convection modules  102  and  104 . If a predetermined cooking time has elapsed in operation  706 , the first and second convection modules  102  and  104  are both stopped, and thus the convection-cooking mode ends in operation  708 . A heating speed of the air in the cooking cavity  114  may be controlled by alternately operating the first and second convection modules  102  and  104 , as described above. Since the cooking apparatus of the present invention generates convection of hot air in a cooking cavity using two convection modules, a temperature distribution in the cooking cavity is uniformly maintained, so that the food may have a uniform cooking quality. 
   Furthermore, since the hot air is generated by using the two convection modules, a heating speed of air surrounding the food is improved, one or all of convection modules may be operated according to need, and the two convection modules may be alternately operated according to need, so that a temperature of the hot air may be controlled even though a heating temperature of a heater is fixed. 
   This invention may be understood to include alternate configurations of first and second modules which have not been explicitly discussed above. With regard to these additional configurations, the modules may be placed at various positions in the cooking cavity as long as a first module discharges air into a convenient area of the cooking cavity for a second module to draw the discharged air in. Similarly, the second module should be positioned so as to discharge air in an area of the cooking cavity that is convenient for the first module to draw the air, which the first module originally discharged, back in. 
   Furthermore, this invention may be understood to include additional modules beyond first and second modules. In such a case, additional modules would be in convenient draw and discharge positions relative to the first and second modules as well as with respect to any other additional modules. 
   Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.