As is well known, the resistance of a resistance element varies based upon the temperature. In the case of a resistance element made of a ferromagnetic material such as nickel-cobalt, the resistance increases nearly linearly with an increase in the temperature. Therefore, there can be contrived a temperature sensor for detecting the temperature by utilizing the temperature characteristics of the resistance element. However, the resistance of the resistance element usually varies depending upon a change in the magnetic field, i.e., depending upon the angular change of the magnetic vector that is imparted. In an environment where the magnetic vector varies, therefore, it becomes difficult to utilize the temperature characteristics of the resistance element.
There has heretofore been proposed a temperature sensor using the resistance element such as the one disclosed in, for example, JP-A-5-249211. This temperature sensor detects the temperature by utilizing the temperature characteristics of the resistance element that is formed maintaining a line width of 6 μm.
Referring to FIG. 8, changes P in the resistance of the resistance element accompanying the angular change of the magnetic vector are represented. The change P in the resistance becomes very small when the line width of the resistance element is smaller than 6 μm in an environment where a magnetic vector of, for example, about 25 Gauss is applied. On the other hand, the resistance of the resistance element varies depending upon a change in the temperature but not dependent upon the line width of the resistance element. Therefore, the resistance of the resistance element formed maintaining a line width of 6 μm varies relying almost upon the temperature only. Therefore, the above temperature sensor makes it possible to detect the temperature by utilizing the temperature characteristics of the resistance element even in an environment where the magnetic vector undergoes the angular change.
As described above, the conventional temperature sensor surely makes it possible to detect the temperature by utilizing the temperature characteristics of the resistance element. However, as shown in FIG. 8, when a magnetic vector of a large intensity (e.g., 50 to 100 Gauss) is imparted to the resistance element, the resistance of the resistance element inevitably varies accompanying the angular change of the magnetic vector even if the line width is maintained to be not larger than 6 μm. That is, when the above conventional temperature sensor is placed in an environment where the magnetic vector having a large magnetic intensity undergoes the angular change, it is still difficult to detect the temperature relying upon the temperature characteristics of the resistance element.
USPTO Backgrounds
USPTO Backgrounds