Liquid ejection head and recording apparatus
A first flow path member of a liquid ejection head includes a plurality of pressurizing chambers connected to a plurality of ejection holes, a plurality of first individual flow paths connected to the plurality of pressurizing chambers, a plurality of second individual flow paths and a plurality of third individual flow paths, a first common flow path connected in common to the plurality of first and second individual flow paths, and a second common flow path connected in common to the plurality of third individual flow paths. A length from an area centroid of a surface pressurized by a displacement element in the pressurizing chamber to the area centroid via the first individual flow path, first common flow path, and second individual flow path in this order is longer than twice a length from the area centroid to the second common flow path via the third individual flow path.
1. A liquid ejection head comprising:
a flow path member comprising
a plurality of ejection holes,
a plurality of pressurizing chambers respectively connected to the plurality of ejection holes,
a plurality of first flow paths respectively connected to the plurality of pressurizing chambers,
a plurality of second flow paths respectively connected to the plurality of pressurizing chambers,
a plurality of third flow paths respectively connected to the plurality of pressurizing chambers,
a fourth flow path connected in common to the plurality of first flow paths and the plurality of second flow paths, and
a fifth flow path connected in common to the plurality of third flow paths; and
a plurality of pressurizing units for respectively pressurizing a liquid inside the plurality of pressurizing chambers, wherein
in one of the plurality of first flow paths, one of the plurality of second flow paths, one of the plurality of third flow paths, which are connected to one of the plurality of pressurizing chambers, and one of the plurality of pressurizing units pressurizing a liquid inside the one of the plurality of pressurizing chambers,
a first length of an annular flow path circulating from an area centroid of a surface pressurized by the one of the pressurizing units in the one of the pressurizing chambers through the one of the first flow paths, the fourth flow path, and the one of the second flow paths, in this order, to the area centroid, is longer than twice a second length extending from the area centroid to the fifth flow path via the one of the third flow paths.
2. The liquid ejection head according to claim 1 , wherein
a length in the fourth flow path of the first length occupies 30% or more of the first length.
3. The liquid ejection head according to claim 1 , wherein
the one of the third flow paths is located between the one of the first flow paths and the one of the second flow paths, in an opening direction of the plurality of ejection holes.
4. The liquid ejection head according to claim 1 , wherein
the fourth flow path extends in a direction perpendicular to an opening direction of the plurality of ejection holes, and
the one of the first flow paths and the one of the second flow paths extend from the fourth flow path to an identical side in a width direction of the fourth flow path, when viewed in the opening direction.
5. The liquid ejection head according to claim 1 , wherein
the fourth flow path extends in a direction perpendicular to an opening direction of the plurality of ejection holes, and
the one of the first flow paths and the one of the second flow paths extend from the one of the pressurizing chambers to mutually different sides in a flow path direction of the fourth flow path, extend to an identical side in a width direction of the fourth flow path, and are connected to the fourth flow path at mutually different positions in the flow path direction, when viewed in the opening direction.
6. The liquid ejection head according to claim 5 , wherein
the fifth flow path extends parallel to the fourth flow path, and
the one of the second flow paths and the one of the third flow paths extend from the one of the pressurizing chambers to mutually opposite sides in the flow path direction of the fourth flow path and the fifth flow path, and extend to mutually opposite sides in the width direction of the fourth flow path and the fifth flow path, when viewed in the opening direction.
7. A recording apparatus comprising:
the liquid ejection head according to claim 1 ;
a transport unit that transports a recording medium to the liquid ejection head; and
a control unit that controls the liquid ejection head.