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US 5,675,143 AGranted
Proximity switch
AssigneeOptosys SA
InventorPeter Heimlicher
Life of this patent
Estimating the term…
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AssigneeOptosys SA
InventorPeter Heimlicher
Estimating the term…
The use of a single concave mirror (1) serving as an optical focusing and directing element for a proximity switch allows an increased sensitivity at equal construction size or a substantial reduction in the construction size with equal sensitivity. In a preferred embodiment, the concave mirror is divided into two halves (3, 4) by a supporting 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) and 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 to 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.
A proximity switch having at least one light source and at least one light sensor, wherein a first portion of a concave mirror is associated to the light source and a second portion of the concave mirror is associated to the light sensor, in such a manner that the light emitted by the light source is directed in a direction to be monitored by the first portion of the concave mirror, and the light which is reflected in the direction of the proximity switch by an object approaching from said monitored direction is directed to the light sensor by the second portion of the concave mirror.
Dependencies are inferred from the claim text.