Methods and apparatuses for control of a signal in a printing apparatus
View Patent ↗A printing apparatus is provided that precisely control the transition of an electrical signal that causes a printing substance to be deposited. In particular, in some embodiments, a circuit is configured to control the application of a firing pulse to a printing element, and the printing element is configured to control the application of a printing substance. The circuit in this embodiment is configured to condition or control the transition of the firing pulse from the first state to the second state such that current through the printing element dissipates to zero over a period of time that is neither too fast nor too slow.
1. A circuit for controlling magnitude of current flowing to an actuator element configured to deposit ink in a printing apparatus, the circuit comprising:
at least one switching device configured to selectively allow and cutoff the flow of current to an actuator based upon a firing signal turning on and off, wherein the actuator is configured to deposit a printing substance in a printing apparatus; and
at least one circuit component having standard sizing relative to other components on the printing apparatus, wherein the component is configured to control the firing signal provided to the switching device in order to cause flow of current to the actuator to dissipate slowly enough such that damaging levels of voltages are not induced in the circuit, wherein the component is further configured to control the firing signal to cause flow of current to the actuator to dissipate quickly enough such that the actuator current reaches substantially zero in under about 1 microsecond; and
wherein the at least one circuit component comprises a component that dissipates current caused by the firing pulse according to a characteristic that approximates a resistor.