Keying methods and apparatus for inkjet print cartridges and inkjet printers

An inkjet printer comprising:

• a base carrying a housing, said housing defining a printing path extending therethrough;
• means for controllably transporting a sheet of print media through said housing along said printing path;
• a traverse mechanism carrying a fluid jet print cartridge for movement generally transversely to said printing path;
• said fluid jet print cartridge including:
• a cartridge body defining a printing fluid chamber, and carrying a print head for controllably ejecting fine-dimension droplets of [the] printing fluid;
• said cartridge body including a plurality of keying locations arrayed in a determined pattern on said cartridge body, and each of said plurality of keying locations alternatively having a positive value represented by an outwardly extending keying feature, or having a null value represented by said array location being free of such an outwardly extending keying feature;
• and
• said traverse mechanism including a carriage having a keying member with a plurality of key engagement structures arrayed in a certain pattern complementary to said determined pattern;
• whereby, said keying member of said carriage is engageable with said keying features of said print cartridge so that said plurality of keying features inter-engage with said key engagement structures.

Structure for keying engagement of an inkjet print cartridge with an inkjet printer, said structure comprising:

• said inkjet print cartridge including:
• a generally rectangular prismatic print cartridge body including plural walls, at least one wall of said inkjet print cartridge carrying an array of plural outwardly extending keying features, with each of said plural keying features alternatively having a positive value or a null value, wherein a positive value for a keying feature corresponds to that keying feature including an upstanding key member extending outwardly on said wall, and a null value for a keying feature corresponds to that keying feature having substantially a zero height;
• said plurality of keying features cooperatively defining a determined pattern of positive values;
• and
• said inkjet printer including:
• a housing defining a printing path extending therethrough and transport apparatus for controllably transporting a sheet of print media along said printing path, a traverse mechanism including a carriage carrying said inkjet print cartridge for movement generally transversely to said printing path, said carriage having a key engagement member with a plurality of key engagement structures arrayed in a certain pattern complementary to said determined pattern;
• whereby, said key engagement member of said carriage is movably engageable with said keying features of said inkjet print cartridge so that those keying features which have a positive value inter-engage with said key engagement structures.

A method for identifying an inkjet print cartridge to an inkjet printer, said method comprising steps of:

• providing said inkjet print cartridge with a body including:
• a generally rectangular prismatic print cartridge body, including plural walls on said print cartridge body, and providing on at least one of said plural walls of said inkjet print cartridge body an array of plural outwardly extending keying features;
• providing for each of said plural keying features of said array to alternatively have a positive value or a null value, wherein a positive value for a keying feature corresponds to that keying feature including an upstanding key member extending outwardly on said wall, and a null value for a keying feature corresponds to that keying feature having substantially a zero height which is an open space in said array;
• providing for said plurality of keying features to cooperatively define a determined pattern of positive and null values;
• and
• providing said inkjet printer with a carriage carrying said inkjet print cartridge;
• providing said carriage with a key engagement member having a plurality of key engagement structures arrayed in a certain pattern complementary to said determined pattern.