Device for the detection of liquid surfaces
AssigneeBoehringer Mannheim GmbH
InventorStefan Heesch
Life of this patent
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Abstract
Device for the detection of liquid surfaces including a light source sending light onto a liquid surface, an oscillation element which is moved toward the liquid surface and causes the liquid surface to oscillate upon contact with the surface. The surface contact is detected by a light detector which picks up the radiation reflected by the liquid. Upon contact with the liquid, the light sent out by the light source is modulated by the oscillations of the liquid surface. The so modulated signal can be selectively identified by the detector.
Claims23
A device for detecting a liquid surface, said device comprising:
- a light source disposed above a liquid surface to be detected;
- detector means above said liquid surface, said detector means for detecting light from said light source which is reflected by the liquid surface, said detector means generating a detection signal based upon the light detected thereby;
- oscillation means disposed above the liquid surface, said oscillation means for contacting the liquid surface;
- excitation means coupled to said oscillation means, said excitation means for exciting said oscillation means and transmitting an oscillation thereto;
- drive means coupled to said oscillation means for moving said oscillation means to and from the liquid surface;
- filter means coupled to said detector means, said filter means receiving the detection signal and outputting a filtered signal by filtering interfering signals therefrom;
- and
- evaluation means coupled to said filter means, said evaluation means detecting a contact between the oscillation means and the liquid surface, the contact being detected based upon the filtered signal.
A method for the detection of a surface of a liquid, said method comprising the steps of:
- oscillating an oscillating member above a liquid surface;
- moving said oscillating member toward the liquid surface;
- exposing a liquid surface to be detected to light from a light source;
- detecting light from said light source which has been reflected from said liquid surface with a detector means, wherein said detector means generates a detection signal;
- filtering the detection signal, thereby producing a filtered signal;
- determining contact between the oscillating member and the liquid surface based upon the filtered signal.
A method for detecting a liquid surface, said method comprising the steps of:
- providing a light source and a detector above a liquid surface, said detector for detecting light from the light source which is reflected by the liquid surface, with the detector generating a detection signal based upon the light detected thereby;
- providing an oscillating member above the liquid surface, said oscillating member being movable to and from the liquid surface;
- providing an excitation means for exciting said oscillating member, by translating an oscillation thereto;
- said method further comprising the steps of
- oscillating said oscillating member through excitation of the excitation means;
- moving the oscillating member toward the liquid surface;
- radiating light from the light source toward the liquid surface;
- detecting light reflected from the liquid surface with the detector such that the detector generates the detection signal;
- filtering the detection signal with a filtering means, and outputting a filtered signal therefrom;
- determining a contact between the oscillating element and the liquid surface based upon the filtered signal.
Dependencies are inferred from the claim text.