Humidity sensor

DETAILED DESCRIPTION The present invention has its base on the discovery or ascertainment that there are many cases where the above defect of the prior art is caused by the fact that the dewdrop formed on the surface of dew detecting element are divided into fine independent condensed particles by the surface tension thereof between the electrodes and accordingly the electrodes are not bridged by the fine condensed dewdrops.
Accordingly, an object of the present invention is to provide a humidity sensor which has a novel dew detecting element or sensor element to improve and enhance the detecting sensitivity of the humidity sensor.
Another object of the invention is to provide a video tape recording and/or reproducing apparatus employing the above humidity sensor which is mounted on its tape guide drum for detecting the humidity thereon.
According to an aspect of the invention, there is provided a humidity sensor which comprises a humidity sensor member formed of a pair of electrodes made of stainless steel or the like and mounted in opposed relation with each other on an insulator film made of, for example, polyester system with a suitable gap.
In this case, the surface of the insulator on the gap between the electrodes is made rough or coarse, so that condensed dewdrops formed on the humidity sensor are dispersed uniformly over the surface thereof to enhance the detecting sensitivity thereof.
According to another aspect of the invention, there is proposed a video tape recording and/or reproducing apparatus which employs the humidity sensor mentioned just above on its tape guide drum for detecting the humidity thereon.
The other objects, features and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings.