日本松下电子部品公司推出一种可在广范围内探测人活动的小型人体探测器。以前采用陶瓷体式红外传感器,其缺点是光敏面积大,相应传感器的体积也大,而且灵敏度具有方向性。而新开发的热释电薄膜(约2μm)传感器,其光敏面积比原来的小,灵敏度与方向的关系也得到了改善。另外,由于光敏面积小,所以必需采用短焦距透镜。但由于以往的聚乙稀透镜在实现短焦距化上有限制,不太适合新开发的小型薄膜热释电探测器,而且透射率也低。该公司 Japan’s Matsushita Electric Industrial Co., Ltd. introduced a small body detector capable of detecting human activities in a wide range. Before the use of ceramic body infrared sensor, the disadvantage is that the photosensitive area, the corresponding sensor is also large, and the sensitivity of a directional. The newly developed pyroelectric thin film (about 2μm) sensor, the photosensitive area smaller than the original, the relationship between sensitivity and direction has also been improved. In addition, because of the small photosensitive area, it is necessary to use a short focal length lens. However, conventional polyethylene lenses have limitations in shortening the focal length and are not suitable for newly developed thin-film pyroelectric detectors with low transmittance. The company