| 摘要 |
PURPOSE:To eliminate effect of noises due to pyroelectric phenomenon, by providing positive and negative electrodes on one surface of a piezo-electric body in the same area while a neutral electrode on the other surface thereof. CONSTITUTION:Positive and negative electrodes 2 and 3 are provided on the one surface of a piezo-electric body 1 in the same area while a neutral electrode 4 on the other surface thereof 1. This can eliminates effect of noises due to pyroelectric phenomenon. In other words, electric charge proportinal to the ambient temperature is generated in the positive and negative electrodes 2 and 3. But since, both the electrodes 2 and 3 are located on the same polarization surface while they are the same in the area, output voltages generated in the both the electrodes 2 and 3 due to pyroelectric phenomenon are equal and will not change being cancelled. This can elimiates effect of noises due to pyroelectric phenomenon. |
