Patent ID: 7199388
Filing Date: 2007-04-03
Classification: G01F

Abstract:
1. A liquid surface level detecting apparatus for detecting a liquid surface level of a liquid existing in an outside, including: a light emitting means for emitting a light; an optically scattering means for scattering the light emitted by said light emitting means; a light radiating means having a liquid surface level detecting unit for radiating a part of a scattering light scattered by said optically scattering means to an outside of said optically scattering means; a light receiving means for receiving said scattering light which is reflected by and returned from a boundary of the outside of said optically scattering means or said light radiating means without being radiated by said light radiating means; and a light shielding means for shielding the light so that the light from said light emitting means is not directly irradiated to said light receiving means, wherein if said liquid exists in said outside, a radiation light amount to the outside of said light radiating means is changed, and that change is detected on the basis of the light reception amount of said light receiving means, thereby detecting said liquid surface level of said liquid.