Ink jet head and ink jet printer
An ink jet head includes an actuator, a driver IC, a first capacitor, a second capacitor, and a fuse. The actuator is configured to cause ink to be discharged from nozzles. The driver IC is configured to drive the actuator. The first capacitor is connected between a ground line and a first node of a power supply line connected to the driver IC. The second capacitor is connected between a ground line and a second node of the power supply line. A capacitance of the second capacitor is less than a capacitance of the first capacitor. The fuse is on the power supply line between the first node and the second node.
1. An ink jet head, comprising:
an actuator configured to cause ink to be discharged from nozzles;
a driver IC connected to a power supply line and configured to drive the actuator;
a first capacitor connected between a ground line and a first node of the power supply line;
a second capacitor connected between the ground line and a second node of the power supply line, the second node being between the first node and the driver IC, a capacitance of the second capacitor being smaller than a capacitance of the first capacitor; and
a fuse on the power supply line between the first node and the second node.
2. The ink jet head according to claim 1 , wherein the ground line is connected to the driver IC, and the first capacitor is connected to a third node of the ground line and the second capacitor is connected to a fourth node of the ground line, and the fourth node is between the third node and the driver IC.
3. The ink jet head according to claim 1 , wherein the capacitance of the second capacitor is in a range of 8% to 25% of the capacitance of the first capacitor.
4. The ink jet head according to claim 1 , wherein the capacitance of the first capacitor and the capacitance of the second capacitor are both variable based on a bias voltage respectively applied thereto, and the capacitance of the second capacitor when being biased is in a range of 9% to 27% of the capacitance of the first capacitor when being biased.
5. The ink jet head according to claim 1 , wherein the driver IC includes:
a logic circuit configured to generate a drive signal;
a level shifter configured to shift a voltage level of the drive signal to generate a level-shifted drive signal; and
a driver configured to operate based on power supplied from the power supply line and output, based on the level-shifted drive signal, a signal of one of a first level, based on a voltage level of the power supply line, and a second level based on a ground voltage level.
6. The ink jet head according to claim 5 , wherein
the logic circuit is configured to operate based on power supplied from a second power supply line different from the power supply line, and
the level shifter is configured to operate based on power supplied from a third power supply line different from the power supply line and the second power supply line.
7. The ink jet head according to claim 1 , further comprising:
a head substrate, wherein the first capacitor, the second capacitor, the fuse, and at least a part of the power supply line are provided on the head substrate.
8. An ink jet head, comprising:
an actuator configured to cause ink to be discharged from nozzles;
a driver IC configured to drive the actuator;
a power supply line connected to the driver IC;
a ground line connected to the driver IC; and
a protection circuit including:
a first capacitor connected between the ground line and a first node of the power supply line;
a second capacitor connected between the ground line and a second node of the power supply line, the second node being between the first node and the driver IC, a capacitance of the second capacitor being less than a capacitance of the first capacitor; and
a fuse on the power supply line between the first node and the second node.
9. The ink jet head according to claim 8 , wherein the first capacitor is connected to a third node of the ground line and the second capacitor is connected to a fourth node, the fourth node being between the third node and the driver IC.
10. The ink jet head according to claim 8 , wherein the capacitance of the second capacitor is in a range of 8% to 25% of the capacitance of the first capacitor.
11. The ink jet head according to claim 8 , wherein the capacitance of the first capacitor and the capacitance of the second capacitor are both variable based on a bias voltage applied thereto, and the capacitance of the second capacitor when being biased is in a range of 9% to 27% of the capacitance of the first capacitor when being biased.
12. The ink jet head according to claim 8 , wherein the driver IC includes:
a logic circuit configured to generate a drive signal;
a level shifter configured to shift a voltage level of the drive signal to generate a level-shifted drive signal; and
a driver configured to operate based on power supplied from the power supply line and output, based on the level-shifted drive signal, a signal of one of a first level based on a voltage level of the power supply line and a second level based on a ground voltage level.
13. The ink jet head according to claim 12 , wherein
the logic circuit is configured to operate based on power supplied from a second power supply line different from the power supply line, and
the level shifter is configured to operate based on power supplied from a third power supply line different from the power supply line and the second power supply line.
14. The ink jet head according to claim 8 , further comprising:
a head substrate, wherein the first capacitor, the second capacitor, the fuse, at least a part of the power supply line, and at least a part of the ground line are provided on the head substrate.
15. An ink jet printer, comprising:
a conveyance motor configured to convey a sheet;
an ink jet head configured to discharge ink onto the sheet; and
a head controller configured to supply power and a control signal to the ink jet head, wherein the ink jet head comprises:
an actuator configured to cause ink to be discharged from nozzles;
a driver IC configured to drive the actuator;
a first capacitor connected between a ground line and a first node of a power supply line connected to the driver IC;
a second capacitor connected between the ground line and a second node of the power supply line, the second node being between the first node and the driver IC, a capacitance of the second capacitor being less than a capacitance of the first capacitor; and
a fuse on the power supply line between the first node and the second node.
16. The ink jet printer according to claim 15 , wherein the first capacitor is connected to a third node of the ground line and the second capacitor is connected to a fourth node of the ground line, the fourth node being between the third node and the driver IC.
17. The ink jet printer according to claim 15 , wherein the capacitance of the second capacitor is in a range of 8% to 25% of the capacitance of the first capacitor.
18. The ink jet printer according to claim 15 , wherein the capacitance of the first capacitor and the capacitance of the second capacitor are both variable based on a bias voltage applied thereto, and the capacitance of the second capacitor when being biased is in a range of 9% to 27% of the capacitance of the first capacitor when being biased.
19. The ink jet printer according to claim 15 , wherein the driver IC includes:
a logic circuit configured to generate a drive signal;
a level shifter configured to shift a voltage level of the drive signal to generate a level-shifted drive signal; and
a driver configured to operate based on power supplied from the power supply line and output, based on the level-shifted drive signal, a signal of one of a first level, based on a voltage level of the power supply line, and a second level, based on a ground voltage level.
20. The ink jet printer according to claim 19 , wherein
the logic circuit is configured to operate based on power supplied from a second power supply line different from the power supply line, and
the level shifter is configured to operate based on power supplied from a third power supply line different from the power supply line and the second power supply line.