Method and apparatus for detecting fluid level
AssigneeHewlett-Packard Company
InventorBruce Cowger
Life of this patent
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Abstract
The present invention is a fluid level detector for providing a signal indicative of fluid level in a fluid container. The fluid level detector includes a first light conduit portion for providing light to fluid within the fluid container and a second light conduit portion for receiving light provided by the first light conduit portion. A light path extends from the first light conduit portion into the second light conduit portion. The light path has a light path length that varies with fluid level within the fluid container. The light path length variation produces light intensity variation at the second conduit portion which is indicative of fluid level in the fluid container.
Claims23
A fluid level detector for providing a signal indicative of fluid level in a fluid container, the fluid level detector comprising:
- a first light conduit portion for providing light to a fluid within the fluid container and a second light conduit portion for receiving light provided by a light source;
- and
- a light path extending from the first light conduit portion to the second light conduit portion, through the fluid within the fluid container the light path having a light path length that varies with fluid level within the fluid container, the light path length variation producing light intensity variation at the second light conduit portion which is indicative of fluid level in the fluid container.
A fluid level detector for providing a fluid level output signal indicative of fluid level, the fluid level detector comprising:
- a light providing conduit for providing light along a light path;
- a light receiving conduit for receiving light along the light path provided by the light providing conduit;
- and
- wherein the light path extending from the light providing conduit to the light receiving conduit extends through fluid, the light path having a first light path length and a corresponding first optical density associated with a first fluid level and a second light path length and a corresponding second optical density associated with a second fluid level with the first optical density being different from the second optical density and wherein the light receiving conduit provides a signal indicative of the first and second optical density which is thereby indicative of the first and second ink levels, respectively.
A method for detecting fluid level in a fluid container comprising:
- providing light to a first end of a light path, the light path having a light path length defined as being along the light path between the first end and a second end of the light path with the light path extending through fluid within the container;
- varying the light path length based on an amount of fluid within the container;
- detecting light intensity at the second end of the light path with light intensity at the second end being indicative of fluid amount in the container.
A fluid level detector for providing a signal indicative of fluid level in a flexible fluid container, the fluid level detector comprising:
- a first light conduit portion for providing light to fluid within the fluid container and a second light conduit portion for receiving light provided by a light source;
- a base member;
- and
- first and second paddle members linked to the first and second light conduit portions, the first and second paddle members being movably attached to the base member, the first and second paddle members having a first position biased outwardly in opposition associated with a container fill condition and a second position compressed inwardly toward each other associated with a fluid container low condition wherein a light path length between the first and second light conduit portions through container fluid is a first length associated with the first position and a second length, different from the first length associated, with the second position.
Dependencies are inferred from the claim text.