Patent ID: 8807720

Claim:
A printing material cartridge detachably mountable in a holder of a printing apparatus, the printing apparatus including a power supply and a mounting detection circuit having a mounting current value detection section that detects a detection current that flows when at least one printing material cartridge among a cartridge set configured of N (N is integer of 2 or more) printing material cartridges is mounted in the holder of a printing apparatus, the mounting detection circuit detecting a mounting state of the cartridge set in the holder according to the detection current, the printing material cartridge comprising: a storage device storing information regarding the printing material cartridge; an electric device for the mounting detection; a plurality of storage device terminals and a plurality of electric device terminals; wherein, the electric device is, (i) arranged to be connected in parallel to which the electric device of another printing material cartridge of the cartridge set between the power supply and the mounting current value detection section when the cartridge set is mounted in the printing apparatus, and (ii) configured such that the detection current is a predetermined threshold value current or more when N printing material cartridges are mounted inside the holder, and wherein the plurality of storage device terminals include a ground terminal and wherein the plurality of electrical device terminals lack a ground terminal connection within the printing material cartridge; wherein the electric device of N printing material cartridges is configured such that the detection current is a different current values depending on which of the printing material cartridges in the cartridge set are mounted in the holder; the printing apparatus further comprising a resistance element of apparatus side; wherein the electric device of n th (n=1 to N) printing material cartridge in N printing material cartridges is a resistance element, wherein the resistance element of n th printing material cartridge is connected the mounting detection resistances in series between the power supply for the mounting detection and the mounting current value detection section; the mounting current value detection section further comprising: a current-voltage converting section that generates the detection voltage by converting the detection current into the voltage; an A-D converting section that compares the mounting detection voltage with a plurality of threshold value voltages and converts it into a digital detection signal; and a voltage correction section that corrects the plurality of threshold value voltages according to variation of the voltage of the power source for the mounting detection, wherein the mounting detection circuit determines the mounting state of the printing material cartridge in the holder based on the digital detection signal.