| 摘要 |
The use of a single concave mirror (1) serving as an optical focusing and directing element for a proximity switch allows to obtain an increased sensitivity at equal construction size or to substantially reduce the construction size with equal sensitivity. In a preferred embodiment, the concave mirror is divided into two halves (3, 4) by the support plate (2) for the light source (5) and the light sensor (6), the halves (3, 4) of the mirror serving the purpose of directing the emitted light (8) resp. that of focusing the reflected light (9) onto the light sensor. In order to increase the resistance to difficult environmental conditions, the concave mirror (1) or its portions (3, 4) can be filled with a substance which is transparent for the light of the light source (5). Metallized plastics material is a suitable material for the mirror, especially in combination with the mentioned filling substance.
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