Cooking appliance

Abstract

A cooking appliance may include a heater; a heating controller configured to control operation of the heater; a safety controller; a heating switch connected between an external power source and the heater; a safety switch connected between the external power source and the heater; and a controller configured to control an open or closed state of the safety switch according to an operation of the heating controller or an operation of the safety controller. The controller may be configured to control the safety switch to be closed when the heating controller is changed to an on state while the safety controller is in an on state and the heating controller is in an off state.

What is claimed is: 
     
         1 . A cooking appliance comprising:
 a heater;   a heating controller configured to control operation of the heater;   a safety controller;   a heating switch connected between an external power source and the heater;   a safety switch connected between the external power source and the heater; and   a controller configured to control an open or closed state of the safety switch according to operation of the heating controller or operation of the safety controller,   wherein when the safety controller is changed from an off state to an on state while the heating controller is in an on state, the controller is configured to maintain the safety controller in an on state during a predetermined first waiting time.   
     
     
         2 . The cooking appliance of  claim 1 , wherein when the heating controller is not changed to the off state for the first waiting time, the controller is configured to change the safety controller to the off state. 
     
     
         3 . The cooking appliance of  claim 1 , wherein when the heating controller is changed to the on state while the safety controller is in the on state and the heating controller is in the off state, the controller is configured to control the safety switch to be closed. 
     
     
         4 . The cooking appliance of  claim 1 , wherein when the heating controller is not changed to the on state during a predetermined second waiting time while the safety controller is in the on state and the heating controller is in the off state, the controller is configured to change the safety controller to the off state. 
     
     
         5 . The cooking appliance of  claim 1 , wherein when both the heating switch and the safety switch are opened while the safety controller is in the on state and both the heating switch and the safety switch are closed, the controller is configured to maintain the safety controller in the on state until a predetermined third waiting time elapses. 
     
     
         6 . The cooking appliance of  claim 5 , wherein when the heating controller is changed to the on state before the third waiting time elapses, the controller is configured to control the heating switch and the safety switch to be closed. 
     
     
         7 . The cooking appliance of  claim 5 , wherein when the heating controller is not changed to the on state until the third waiting time elapses, the controller is configured to change the safety controller to the off state. 
     
     
         8 . The cooking appliance of  claim 1 , wherein when the heating controller is changed to the on state, the controller is configured to control the heating switch to be closed. 
     
     
         9 . The cooking appliance of  claim 1 , wherein the cooking appliance further comprises an operation indicator lamp indicating an operating state of the heater, an operating state of the heating controller, or an open or closed state of the safety switch. 
     
     
         10 . The cooking appliance of  claim 1 , wherein the cooking appliance further comprises a safety controller status display area configured to display a status of the safety controller, and
 wherein the safety controller status display area is turned on while the safety controller is in an on state and is turned off while the safety controller is in an off state.   
     
     
         11 . A cooking appliance comprising:
 a heater;   a heating controller configured to control operation of the heater;   a safety controller; and   a controller configured to control operation of the heater according to operation of the heating controller or operation of the safety controller,   wherein the heater works only while the safety controller is in an on state,   wherein when the safety controller is changed from an off state to the on state while the heating controller is in an on state, the controller is configured to maintain the safety controller in the on state during a predetermined first waiting time.   
     
     
         12 . The cooking appliance of  claim 11 , wherein when the heating controller is not changed to the off state for the first waiting time, the controller is configured to change the safety controller to the off state. 
     
     
         13 . The cooking appliance of  claim 11 , wherein when the heating controller is changed to the on state while the safety controller is in the on state and the heating controller is in the off state, the controller is configured to control the heater to be activated. 
     
     
         14 . The cooking appliance of  claim 11 , wherein when the heating controller is not changed to the on state during a predetermined second waiting time while the safety controller is in the on state and the heating controller is in the off state, the controller is configured to change the safety controller to the off state. 
     
     
         15 . The cooking appliance of  claim 11 , wherein when both the heating switch and the safety switch are opened while the safety controller is in the on state and both the heating switch and the safety switch are closed, the controller is configured to maintain the safety controller in the on state until a predetermined third waiting time elapses. 
     
     
         16 . The cooking appliance of  claim 15 , wherein when the heating controller is changed to the on state before the third waiting time elapses, the controller is configured to control the heater to be activated. 
     
     
         17 . The cooking appliance of  claim 15 , wherein when the heating controller is not changed to the on state until the third waiting time elapses, the controller is configured to change the safety controller to the off state. 
     
     
         18 . The cooking appliance of  claim 11 , wherein the cooking appliance further comprises an operation indicator lamp indicating an operating state of the heater, an operating state of the heating controller, or an open or closed state of the safety switch. 
     
     
         19 . The cooking appliance of  claim 11 , wherein the cooking appliance further comprises a safety controller status display area configured to display a status of the safety controller, and wherein the safety controller status display area is turned on while the safety controller is in an on state and is turned off while the safety controller is in an off state.