Patent ID: 8151872

Claim:
An apparatus to control a temperature of a device, which apparatus comprises: a thermal head adapted to be thermally contacted to the device; a combined path to the thermal head; a first path maintained at a first temperature and connected to the combined path; a second path maintained at a second temperature different from the first predetermined temperature and connected to the combined path; a third path connected to the combined path; a pump assembly capable of circulating thermal transfer fluid: (i) from the thermal head, (ii) through each of the first, second and third paths, (iii) from each of the first, second and third paths, through the combined path, and (iv) from the combined path, to and through the thermal head; and a valve assembly capable of controlling amounts of thermal transfer fluid that flow into the first and second paths, thereby controlling the temperature; wherein: the pump assembly is disposed to receive thermal transfer fluid from the thermal head and to output thermal transfer fluid for input to the valve assembly; the first path comprises a first path heat exchanger and the second path comprises a second path heat exchanger; and the apparatus further comprises: a first path temperature sensor operable to sense the first temperature of the first path heat exchanger; a second path temperature sensor operable to sense the second temperature of the second path heat exchanger; a combined path temperature sensor operable to sense a combined path temperature; a thermal head temperature sensor operable to sense a temperature of the thermal head; and a controller in communication with the first path temperature sensor, the second path temperature sensor, the combined path temperature sensor, the thermal head temperature sensor, and the valve assembly.