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US 5,980,013 AGranted
Driving method for ink ejection device and capable of ejecting ink droplets regardless of change in temperature
AssigneeBrother Kogyo Kabushiki Kaisha
InventorYoshikazu Takahashi
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Abstract
In view of the fact that the ink viscosity is high when atmospheric temperature is low whereas the same is low when the atmospheric temperature is high, two types of driving signals are selectively applied to an actuator depending on the temperature so that ink droplets are ejected at a constant speed regardless of change in atmospheric temperature. Alternatively, when the temperature is below a predetermined value, ink droplets are ejected while heating the ink filling an ink channel. When the ink temperature is increased above the predetermined value, heating of the ink is halted.
Claims18
A method of driving an ink ejection device that includes:
- walls defining an ink channel, the ink channel having a volume filled with ink and a length defined by two ends opposite to each other;
- a nozzle plate attached to one end of the ink channel and formed with a nozzle;
- an actuator for changing the volume of the ink channel;
- and
- a driving circuit for driving said actuator by applying thereto pulses of voltage,
- the method comprising the steps of:
- (a) when atmospheric temperature is under a predetermined value, said driving circuit applying a first pulse of voltage to said actuator, wherein said first pulse of voltage has a start edge, a termination edge, a first crest value, and a first duration of time between the start edge and the termination edge, the first duration of time being equal to a pressure wave propagating time required for a pressure wave imparted to the ink filled in said ink channel to propagate over the length of the ink channel;
- and
- (b) when the atmospheric temperature is above the predetermined value, said driving circuit applying a second pulse of voltage to said actuator, wherein said second pulse of voltage has a start edge, a termination edge, a second crest value equal to the first crest value, and a second duration of time between the start edge and the termination edge of said second pulse of voltage, the second duration of time being three times as long as the pressure wave propagating time.
6 more elements
A method of driving an ink ejection device that includes:
- walls defining an ink channel, the ink channel having a volume filled with ink and a length defined by two ends opposite to each other, the ink having a viscosity;
- a nozzle plate attached to one end of the ink channel and formed with a nozzle;
- an actuator for changing the volume of the ink channel;
- a voltage source for supplying a voltage having a predetermined voltage level;
- and
- a driving circuit, disposed in the vicinity of said actuator, for driving said actuator;
- the method comprising the steps of:
- (a) monitoring temperature of ink and determining whether the temperature of ink is above a predetermined value;
- (b) when determination made in step (a) indicates that the temperature of ink is under a predetermined value, heating the ink filling in the ink channel to lower the viscosity of the ink;
- and
- (c) when determination made in step (a) indicates that the temperature of ink is above the predetermined value, said driving circuit applying an ejection pulse signal to said actuator, causing to eject an ink droplet from the nozzle.
8 more elements
A method of driving an ink ejection device that includes:
- walls defining an ink channel, the ink channel having a volume filled with ink and a length defined by two ends opposite to each other, the ink having a viscosity;
- a nozzle plate attached to one end of the ink channel and formed with a nozzle;
- an actuator for changing the volume of the ink channel;
- a voltage source for supplying a voltage having a predetermined voltage level;
- and
- a driving circuit for driving said actuator;
- the method comprising the steps of:
- (a) when atmospheric temperature is under a predetermined value, said driving circuit applying a first pulse train to said actuator, the first pulse train consisting of a first number of pulse signals including an ejection pulse signal and at least one non-ejection pulse signal, said ejection pulse signal and said at least one non-ejection pulse signal being produced from the voltage supplied by said voltage source so as to have a crest value substantially equal to the predetermined voltage level, wherein said ejection pulse signal, when applied to said actuator, causes to eject an ink droplet from the nozzle, said at least one non-ejection pulse signal, when applied to said actuator, does not cause to eject the ink droplet from the nozzle, and said driving circuit generates heat resulting from application of said at least one non-ejection signal to said actuator, the heat being applied to the ink filling in the ink channel to lower the viscosity of the ink;
- and
- (b) when the atmospheric temperature is above the predetermined value, said driving circuit applying a second pulse train to said actuator, the second pulse train consisting of a second number of pulse signals smaller than the first number of pulse signals, the second pulse train including the ejection pulse signal which, when applied to said actuator, causes to eject the ink droplet from the nozzle 14.
7 more elements
Dependencies are inferred from the claim text.