1. Field of the Invention
The invention relates to a sliding window and, more particularly, to one which is adapted for use in automobiles and is raised and lowered electrically, and is equipped with a safety device and a height detector.
2 Description of the Prior Art
Sliding windows used, illustratively in automobiles and equipped with safety devices, have been described in U.S. Pat. No. 3,651,389 and in German Pat. application No. P 29 39 942. As described therein, a capacitive pickup comprising a conductive strip is placed on the surface of the window and runs along its upper edge. Connected to this pickup is a conductive connecting line which is oriented along a vertical or oblique edge of the window to a point where a connection is made to a cable which connects the pickup to an electronic proximity detecting circuit.
Proximity safety devices of this sort should respond even if the pickup does not come in direct conductive contact with a part of a human's body. This occurs, for example, when the edge of the glass is touched with, for example, a gloved hand. In order for the safety device to respond under this condition, the proximity detector should have a very high sensitivity, i.e., a very high gain. However, if the detector is set to such a gain, adverse affects, such as circuit instabilities and spurious signals, which are unrelated to the approach of a part of the body, will cause the detector to produce an erroneous indication. In addition, windows having safety devices of this sort cannot be mass produced by known standard processes.