US 12,691,678 B2Granted

Inkjet head driving circuit that avoids unwanted high-frequency actuator vibration

AssigneeRISO Technologies Corporation

InventorSota Harada

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Abstract

According to one embodiment, an inkjet head driving circuit includes a waveform pattern generation unit configured to generate a waveform pattern based on input data and a driving waveform generation unit configured to generate a driving waveform for driving an actuator of an inkjet head based on the generated waveform pattern. The driving waveform generation unit includes a power source configured to supply a driving voltage for the actuator, a plurality of switch elements for connecting the power source to the actuator, and a driving waveform output unit that outputs the driving waveform to the actuator by switching of the plurality of switch elements based on the waveform pattern. The waveform pattern changes the number of switch elements that are turned on in a section of the driving waveform within one cycle of the driving waveform for causing the actuator to eject an ink droplet.

Claims15

Dependent claims

An inkjet head driving circuit, comprising:

a waveform pattern generation circuit configured to generate a waveform pattern based on input data;
and
a driving waveform generation circuit configured to generate a driving waveform for driving an actuator of an inkjet head based on the generated waveform pattern, wherein
the driving waveform generation circuit includes:
a power source configured to supply a driving voltage for the actuator, and
a driving waveform output circuit including a plurality of switch elements for connecting the power source to the actuator, the driving waveform output circuit being configured to output the driving waveform to the actuator by switching of the plurality of switch elements based on the waveform pattern,
the waveform pattern changes the number of switch elements among the plurality of switch elements that are turned on in at least one section of the driving waveform among a plurality of sections within one cycle of the driving waveform for causing the actuator to eject an ink droplet,
the power source comprises a first power source that supplies a first voltage and a second power source that supplies a second voltage,
the plurality of switches includes:
a first pair of switch elements connected in parallel with the actuator,
a second pair of switch elements connected in parallel between the actuator and the first power source, and
a third pair of switch elements connected in parallel between the actuator and the second power source,
in the first pair of switch elements, ON resistance of one switch element is different from ON resistance of the other switch element,
in the second pair of switch elements, ON resistance of one switch element is different from ON resistance of the other switch element, and
in the third pair of switch elements, ON resistance of one switch element is different from ON resistance of the other switch element.

12 more elements

An inkjet head driving circuit, comprising:

a logical unit circuit configured to generate control signals for driving a plurality of actuators of an inkjet head for ejecting liquid;
and
an analog unit circuit configured to receive the control signals from the logical unit circuit and to output a drive waveform for an actuator of the inkjet head corresponding to the control signals, wherein
the analog unit circuit includes a plurality of switches including:
a first switch connected between a first terminal of the actuator and a second terminal of the actuator;
a second switch connected in parallel with the first switch between the first terminal of the actuator and the second terminal of the actuator;
a third switch connected between the first terminal of the actuator and a first power supply line;
a fourth switch connected in parallel with the third switch between the first terminal of the actuator and the first power supply line;
a fifth switch connected between the first terminal of the actuator and a second power supply line;
and
a sixth switch connected in parallel with the fifth switch between the first terminal of the actuator and the second power supply line, wherein
the second terminal of the actuator is connected to a third power supply line,
the control signals from the logical unit circuit change the number of switches among the plurality of switches that are turned on in at least one section of the driving waveform among a plurality of sections within one cycle of the driving waveform for causing the actuator to eject an ink droplet,
ON resistance of first switch is different from ON resistance of the second switch,
ON resistance of third switch is different from ON resistance of the fourth switch,
ON resistance of fifth switch is different from ON resistance of the sixth switch,
the first power supply line is connected to a first potential,
the third power supply line is connected to a second potential, and
the second power supply line is connected to a third potential that is between the first and second potentials.

16 more elements

An inkjet printer, comprising:

an inkjet head configured to eject liquid, the inkjet head including:
an actuator group with a plurality actuators;
and
a head driving circuit configured to drive the plurality of actuators to eject liquid from pressure chambers associated with the plurality of actuators, wherein the head driving circuit includes:
a logical unit circuit configured to generate control signals for driving the plurality of actuators for ejecting liquid;
and
an analog unit circuit configured to receive the control signals from the logical unit circuit and to output a drive waveform for an actuator corresponding to the control signals,
the analog unit circuit includes a plurality of switches including:
a first switch connected between a first terminal of the actuator and a second terminal of the actuator;
a second switch connected in parallel with the first switch between the first terminal of the actuator and the second terminal of the actuator;
a third switch connected between the first terminal of the actuator and a first power supply line;
a fourth switch connected in parallel with the third switch between the first terminal of the actuator and the first power supply line;
a fifth switch connected between the first terminal of the actuator and a second power supply line;
and
a sixth switch connected in parallel with the fifth switch between the first terminal of the actuator and the second power supply line, wherein
the second terminal of the actuator is connected to a third power supply line, and
the control signals from the logical unit circuit change the number of switches among the plurality of switches that are turned on in at least one section of the driving waveform among a plurality of sections within one cycle of the driving waveform for causing the actuator to eject an ink droplet,
ON resistance of first switch is different from ON resistance of the second switch,
ON resistance of third switch is different from ON resistance of the fourth switch,
ON resistance of fifth switch is different from ON resistance of the sixth switch,
the first power supply line is connected to a first potential,
the third power supply line is connected to a second potential, and
the second power supply line is connected to a third potential that is between the first and second potentials.

20 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/664,168Filed 14 May 2024
Priority: JP 2023-1443306 Sep 2023
Published: US 2025/0074043 A16 Mar 2025
Granted: 28 Jul 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

B41J 2/0455
Control methods or devices therefor, e.g. driver circuits, control circuits: details of switching sections of circuit, e.g. transistors
B41J 2/04541
Control methods or devices therefor, e.g. driver circuits, control circuits: specific driving circuit
B41J 2/04548
Control methods or devices therefor, e.g. driver circuits, control circuits: details of power line section of control circuit
B41J 2/04581
Control methods or devices therefor, e.g. driver circuits, control circuits: controlling heads based on piezoelectric elements