Abstract: The invention described in the specification relates to an apparatus for supplying electrical information to a printer controller in order to identify the one or more cartridges installed in a printer. The apparatus comprises a carriage which is laterally translatable relative to the movement of print media through the printer, carriage translation means, and a replaceable cartridge attached to the carriage. The apparatus further comprises an indicia device which is attached to the replaceable cartridge and which has optically readable indicia thereon containing encoded information which contains information identifying the type of cartridge installed in the printer. The apparatus also includes an optical code reader which reads and transmits the encoded information to a printer controller as the cartridge moves in a lateral direction relative to the code reader.

Abstract: 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.