Method and apparatus for temperature control of heater

A temperature control apparatus for implementing temperature control on a means for heating that heats an object to be heated, comprising;

• at least two means for heating each with a resistance value increasing as the temperature rises;
• at least one means for temperature detection that detects the temperature of the object to be heated;
• a means for target voltage calculation that calculates a target voltage for each of said means for heating by correcting a reference voltage determined based upon the set temperature for the object to be heated with a correction value obtained in correspondence to the temperature detected by said means for temperature detection and multiplying the corrected reference voltage by a temperature distribution constant that is determined in advance for each of said means for heating to adjust the temperature distribution at the object to be heated;
• a means for voltage detection that detects an actual voltage applied to each of said means for heating;
• and
• a means for power control that controls the power applied to each of said means for heating so that the actual voltage at said means for heating conforms to the target voltage.

A temperature control method for implementing temperature control on a means for heating that heats an object to be heated, comprising;

• a step in which a reference resistance determined based upon the set temperature for the object to be heated is corrected by using a correction value obtained in correspondence to the temperature of the object to be heated detected by, at least, one means for temperature detection;
• a step in which the corrected reference resistance is multiplied by a temperature distribution constant used to adjust the temperature distribution at the object to be heated, which is determined in advance for each of at least two means for heating each with a resistance that increases in correspondence to a temperature increase to obtain a target resistance for each of said means for heating;
• a step in which the actual resistance at each of said means for heating is ascertained based upon a feedback voltage which corresponds to the voltage applied to said means for heating and a feedback current which corresponds to the current flowing through said means for heating;
• and
• a step in which the power applied to each of said means for heating is controlled so that the actual resistance at said means for heating conforms to the target resistance.

A temperature control method for implementing temperature control on a means for heating that heats an object to be heated, comprising;

• a step in which a reference voltage determined based upon the set temperature for the object to be heated is corrected by using a correction value obtained in correspondence to the temperature of the object to be heated detected by, at least, one means for temperature detection;
• a step in which the corrected reference voltage is multiplied by a temperature distribution constant used to adjust the temperature distribution at the object to be heated, which is determined in advance for each of at least two means for heating each with a resistance that increases in correspondence to a temperature increase to obtain a target voltage for each of said means for heating;
• a step in which the actual voltage applied to each of said means for heating is detected;
• and
• a step in which the power applied to each of said means for heating is controlled so that the actual voltage at said means for heating conforms to the target voltage.