Patent ID: 8253072
Filing Date: 2012-08-28
Classification: G06F

Abstract:
1. A data input device for heating at least one surface of the data input device, the data input device comprising: a heating circuit comprising: a temperature control circuit comprising: wherein upon the condition that a temperature of the data input device is lower than the determined temperature, a reverse resistance of the first diode is high such that a voltage at the control pin of the integrated circuit chip is lower than a bias voltage of the integrated circuit chip, thus the integrated circuit chip is turned off, the relay is closed to activate the heating apparatus; the reverse resistance of the first diode reduces as the temperature of the data input device increases, thereby the voltage at the control pin of the integrated circuit chip increases; wherein upon the condition that the temperature of the data input device reaches the determined temperature, the voltage at the control pin of the integrated circuit chip exceeds the bias voltage to activate the integrated circuit chip, resulting in the power pin connected to the at least one I/O pins of the integrated circuit chip, which causes a part of current from the power supply to pass through the second resistor, thus reducing the amount of current through the relay, at which point the relay opens to shut off the heating apparatus.