Patent ID: 7651191

Claim:
A temperature detector comprising: a temperature sensor, an output signal of which changes in level in accordance with change in temperature of a detection object; a reference signal generation circuit which generates a level-changeable reference signal; a level memory which rewritably stores therein a first signal level and a second signal level which determine a range where a level of the reference signal changes; a control circuit which controls the reference signal generation circuit so as to make a level of the reference signal change from the first signal level to the second signal level stored in the level memory; a comparator circuit which compares the level of the reference signal and a level of the output signal; and a level rewriter which rewrites at least either one of the first signal level and the second signal level stored in the level memory, wherein the control circuit determines that the level of the reference signal has reached the level of the output signal in accordance with a result of comparison at the comparator circuit and generates, as a detected temperature signal indicating a current temperature of the detection object, a signal corresponding to the level of the reference signal generated by the reference signal generation circuit at a time when the level of the reference signal reaches the level of the output signal, and in addition the control circuit controls the level rewriter so as to change a range where a level of the reference signal changes in accordance with the signal indicating a temperature of the detection object.