| 摘要 |
PROBLEM TO BE SOLVED: To provide a structure capable of suppressing decrease in the gain, when covering a SAW element with a coating film.SOLUTION: A reflection part 7 is configured so that the center of reflection component of a SAW by the reflection part 7 of a temperature characteristics suppression film 5 is deviated from the center of the excitation component of a SAW generated from an IDT 3, in the propagation direction. With such a reflection part 7, a strong SAW is propagated to the propagation path or the reflector 4 side, but only a weak SAW is propagated to the side opposite to the propagation path or reflector 4, and thereby the propagation direction can be limited to one direction. Since the excited energy of the SAW is saved, the energy available for torque detection can be increased compared with the case where there are two propagation directions. Consequently, decrease in the gain of torque detection by the SAW element 1 can be suppressed.SELECTED DRAWING: Figure 2 |
