Patent ID: 8648321

Claim:
A washing machine and/or dishwasher having a wall delimiting a space flushed with water, the washing machine and/or dishwasher comprising: an optical sensor which is mounted to the wall delimiting the space flushed with water of the washing machine and/or dishwasher, the optical sensor comprising: a housing; a light-emitting element; a light-receiving element; and a light-conducting structure, made from a transparent material, having a light entry point, a first reflection surface, a second reflection surface and a light exit point, a collecting-lens mechanism at the light entry point of the light-conducting structure coupling light from the light-emitting element into the light conducting structure where a divergent light beam coming from the light-emitting element is converted by the collecting-lens function of the entry point into a substantially parallel light beam; the light-emitting element, the light-receiving element and the light-conducting structure defining a light measurement path that runs, in this sequence, from the light-emitting element, via the light entry point, the first reflection surface, the second reflection surface and the light exit point, to the light-receiving element; on a section located between the first reflection surface and the second reflection surface, the light measurement path running outside the housing and in the space flushed with water; the light-emitting element, the collecting-lens mechanism at the light entry point of the light-conducting structure, and the first reflection surface producing a light beam that at each point on the section of the light measurement path that runs outside the housing from the first reflection surface to the second reflection surface having a cross-sectional area of not less than 0.9 mm 2 wherein the light beam arriving at the light-receiving element is at least 50% of the light beam from the light-emitting element and wherein the cross-sectional area of the light beam reduces a disturbing influence of particles and/or foam bubbles crossing the light measurement path.