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US 6,293,143 B1Granted
Ink level sensing device and method therefor
AssigneeLexmark International, Inc.
InventorsGary Allen Denton, Wilson Morgan Routt, Jr.
Life of this patent
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AssigneeLexmark International, Inc.
InventorsGary Allen Denton, Wilson Morgan Routt, Jr.
Estimating the term…
The invention relates to an ink level sensing apparatus including an ink cartridge having an ink chamber containing ink and having at least one substantially transparent side panel adjacent the ink chamber. A fluorescent material is disposed in the ink chamber, the fluorescent material being substantially insoluble in the ink and having a specific gravity which is sufficiently lower than the ink to provide an interface between the ink and the fluorescent material. A relatively narrow band light source for emitting light at a first wavelength along a light path through the substantially transparent side panel of the ink cartridge is provided for exciting the fluorescent material. A photosensor for receiving light emitted from a fluorescent material at a second wavelength when the excited fluorescent material crosses the light path is provided, wherein the first and second wavelengths are substantially different. The apparatus provides a means for sensing ink level in an ink cartridge in a reliable relatively inexpensive way.
An ink level sensing apparatus comprising an ink cartridge having an ink chamber containing ink and having at least one substantially transparent side panel adjacent the ink chamber, a fluorescent material in the ink chamber, the fluorescent material being substantially insoluble in the ink and having a specific gravity which is sufficiently lower than the ink to provide an interface between the ink and the fluorescent material, a relatively narrow band light source for emitting light at a first wavelength along a light path through the substantially transparent side panel of the ink cartridge, the emitted light being sufficient to excite the fluorescent material and a photosensor for receiving light emitted from a fluorescent material at a second wavelength when the excited fluorescent material crosses the light path, wherein the first and second wavelengths are substantially different.
A method for sensing a liquid ink level in an ink jet cartridge which comprises
An ink level sensing device for an ink jet printer ink supply comprising an ink supply chamber containing ink and having at least one substantially transparent side panel adjacent the chamber, a fluorescent dye composition in the chamber, the fluorescent dye composition being substantially insoluble in the ink and having a specific gravity which is sufficiently lower than the ink to provide an interface between the ink and the fluorescent dye composition, a relatively narrow band light source for emitting light at a first wavelength sufficient to excite the fluorescent dye composition through the substantially transparent side panel of the ink cartridge, a filter for transmission therethrough a fluorescent emission having a wavelength above about 700 nanometers while retarding a flow of wavelength ranging from about 300 to about 700 nm therethrough and a photosensor for receiving light emitted from the excited fluorescent dye composition when the dye composition crosses the light path of the light source.
An ink level sensing apparatus for an ink jet printer comprising an ink cartridge having an ink chamber containing ink and an energy-excitable material in the ink chamber, the energy-excitable material being substantially insoluble in the ink and having a specific gravity which is sufficiently lower than the ink so as to provide an interface between the ink and the energy-excitable material at a position in the ink chamber substantially corresponding to the level of the ink in the chamber, an energy source configured for exciting the energy-excitable material in the ink chamber, and a detector for receiving energy from the energy-excitable material and for providing an output indicating the position of the energy-excitable material in the ink chamber.
Dependencies are inferred from the claim text.