초록 ▼

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 substan

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.

대표청구항 ▼

[ What is claimed is:] [1.]1. 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

[ What is claimed is:] [1.]1. 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.