Ice maker and refrigerator

Abstract

A refrigerator includes a cabinet forming a storage space, a door configured to open or close the storage space, and an ice maker provided in the storage space or the door. The ice maker includes an upper tray including an upper chamber forming an upper portion of an ice chamber, a lower tray including a lower chamber forming a lower portion of the ice chamber, and an upper heater disposed along a circumference of the upper chamber so that at least two heating regions are formed at different positions in a vertical direction in the upper chamber.

What is claimed is: 
     
         1 . A refrigerator comprising:
 a first tray configured to define a first portion of an ice chamber;   a second tray configured to define a second portion of the ice chamber;   a first heater to supply heat to the ice chamber; and   a second heater to supply heat to the ice chamber,   wherein an ice separation process is performed after an ice making process is completed,   wherein the ice separation process includes:
 a preheating process in which the first heater and the second heater are turned on such that the heat is supplied to the ice chamber, and 
 a moving process in which the second tray moves to an ice separation position such that the ice is separated after a completion of the preheating process, 
   wherein the first heater and the second heater are operated during the moving process, and   wherein a heating amount of the second heater supplied to the ice chamber in the preheating process is less than a heating amount of the first heater supplied to the ice chamber in the preheating process.   
     
     
         2 . The refrigerator of  claim 1 , wherein the first heater is configured to supply heat to the first tray, and the second heater is configured to supply heat to the second tray. 
     
     
         3 . The refrigerator of  claim 1 , wherein the heating amount of the second heater is adjusted through on/off duty control. 
     
     
         4 . The refrigerator of  claim 3 , wherein in one duty cycle, an on-time of the second heater is greater than an off-time of the second heater. 
     
     
         5 . The refrigerator of  claim 1 , wherein the first tray is made of a plastic material, and the second tray is made of an elastic material. 
     
     
         6 . The refrigerator of  claim 1 , wherein turned-on states of the first and second heaters are maintained in the moving process. 
     
     
         7 . The refrigerator of  claim 6 , wherein a heating amount of the second heater in the moving process is greater than the heating amount of the second heater in the preheating process. 
     
     
         8 . The refrigerator of  claim 1 , wherein the preheating process is performed for a time equal to or greater than a first preheating time, and
 wherein, after the first preheating time has elapsed, when a preset preheating completion condition is satisfied, the preheating process is completed.   
     
     
         9 . The refrigerator of  claim 8 , wherein, when a second preheating time has elapsed, it is determined that the preset preheating completion condition is satisfied. 
     
     
         10 . The refrigerator of  claim 8 , wherein when a temperature sensed by a temperature sensor reaches a preset preheating completion temperature, it is determined that the preset preheating completion condition is satisfied. 
     
     
         11 . The refrigerator of  claim 10 , wherein the temperature sensor is configured to detect a temperature of the first tray. 
     
     
         12 . The refrigerator of  claim 1 , wherein the ice separation process comprises a fan detecting process to detect an operation status of a freezer fan, and
 wherein the preheating process is performed when an operation of the freezer fan is detected to be in the off state in the fan detection process.   
     
     
         13 . The refrigerator of  claim 12 , wherein the ice separation process further comprises a waiting time detecting process performed after the ice making process is completed and before the fan detecting process is performed. 
     
     
         14 . The refrigerator of  claim 13 , wherein when it is determined that a waiting time is exceeded a preheating waiting time, the fan detecting process is skipped and the preheating process is performed. 
     
     
         15 . The refrigerator of  claim 13 , wherein the ice separation process further comprises a door detecting process to detect whether a door is opened or closed, and
 wherein the door detecting process is performed before the fan detecting process is performed.   
     
     
         16 . The refrigerator of  claim 15 , wherein the door comprises a freezer door. 
     
     
         17 . The refrigerator of  claim 15 , wherein it is determined that the door is closed in the door detecting process, the fan detecting process is performed. 
     
     
         18 . The refrigerator of  claim 15 , wherein it is determined that the door is opened in the door detecting process, the waiting time detecting process is performed. 
     
     
         19 . The refrigerator of  claim 1 , wherein the second heater is capable of being operated in the ice making process. 
     
     
         20 . An ice maker comprising:
 a first tray configured to define a portion of an ice chamber;   a second tray configured to define another portion of the ice chamber;   a first heater to supply heat to the ice chamber; and   a second heater to supply heat to the ice chamber,   wherein an ice separation process is performed after an ice making process is completed,   wherein the ice separation process includes:
 a preheating process in which the first heater and the second heater are turned on such that the heat is supplied to the ice chamber, and 
 a moving process in which the second tray moves to an ice separation position such that the ice is separated after the preheating process is performed, 
   wherein the first heater and the second heater are operated during the moving process, and   wherein a heating amount of the second heater supplied to the ice chamber in the preheating process is less than a heating amount of the first heater supplied to the ice chamber in the preheating process.