Liquid ejection device

1. A liquid ejection device comprising:

a first channel member having a plurality of first pressure chambers constituting a first pressure-chamber row and a second pressure-chamber row, wherein the first and second pressure-chamber rows extend along a first direction and the second pressure-chamber row is next to the first pressure-chamber row in a second direction orthogonal to the first direction;

a second channel member positioned next to the first channel member in the second direction, the second channel member having a plurality of second pressure chambers constituting a third pressure-chamber row and a fourth pressure-chamber row, wherein the third and fourth pressure-chamber rows extend along the first direction and the fourth pressure-chamber row is next to the third pressure-chamber row in the second direction;

a plurality of first piezoelectric elements positioned corresponding to the plurality of first pressure chambers, respectively, the plurality of first piezoelectric elements constituting a first piezoelectric-element row and a second piezoelectric-element row, the second piezoelectric-element row is next to the first piezoelectric-element row in the second direction;

a plurality of second piezoelectric elements positioned corresponding to the plurality of second pressure chambers, respectively, the plurality of second piezoelectric elements constituting a third piezoelectric-element row and a fourth piezoelectric-element row, the fourth piezoelectric-element row is next to the third piezoelectric-element row in the second direction;

a plurality of first contacts connected to the plurality of first piezoelectric elements, respectively, and positioned at a more outer position than the first piezoelectric element row and the second piezoelectric element row from a center of the liquid ejection device in the second direction; and

a plurality of second contacts connected to the plurality of second piezoelectric elements, respectively, and positioned at a more outer position than the third piezoelectric element row and the fourth piezoelectric element row from the center of the liquid ejection device in the second direction.

2. The liquid ejection device according to claim 1 , further comprising a liquid chamber member disposed opposite to the first piezoelectric elements and the second piezoelectric elements relative to the first channel member and the second channel member, the liquid chamber member having a common liquid chamber communicating in common with pressure chambers included in the second pressure chamber row.

3. The liquid ejection device according to claim 2 , wherein the liquid chamber member has opposite end portions in the first direction, wherein one of the opposite end portions of the liquid chamber member in the first direction includes a first protruding portion, wherein the first protruding portion protrudes outwardly in the first direction relative to an edge of the first channel member and an edge of the second channel member, and

wherein the first protruding portion of the liquid chamber member has an opening communicating with the common liquid chamber.

4. The liquid ejection device according to claim 3 , wherein the other of the opposite end portions of the liquid chamber member in the first direction includes a second protruding portion, wherein the second protruding portion protrudes outwardly in the first direction relative to another edge of the first channel member and another edge of the second channel member, and

wherein the second protruding portion of the liquid chamber member has another opening communicating with the common liquid chamber.

5. The liquid ejection device according to claim 2 , wherein the second pressure chamber row is positioned closer to a center of the liquid chamber member than the first pressure chamber row in the second direction,

wherein the third pressure chamber row is positioned closer to the center of the liquid chamber member than the fourth pressure chamber row in the second direction, and

wherein the common liquid chamber extending from the second pressure chamber row to the third pressure chamber row in the second direction.

6. The liquid ejection device according to claim 5 , wherein the second pressure chamber row and the third pressure chamber row communicate with the same common liquid chamber.

7. The liquid ejection device according to claim 5 , wherein a support is disposed in the common liquid chamber and between the first channel member and the second channel member in the second direction.

8. The liquid ejection device according to claim 5 , wherein the liquid chamber member includes a projecting portion at a wall thereof, wherein the wall defines a portion of the common liquid chamber, and

wherein the projecting portion is positioned between the first channel member and the second channel member in the second direction and the projecting portion extends towards an opposite wall opposing to the wall.

9. The liquid ejection device according to claim 2 , wherein the liquid chamber member further include another common liquid chamber and a partition wall,

wherein the another common liquid chamber is positioned next to the common liquid chamber in the second direction, and

wherein the partition wall separates the common liquid chamber and the another common liquid chamber from each other and is positioned between the common liquid chamber and the another common liquid chamber in the second direction.

10. The liquid ejection device according to claim 1 , wherein pressure chambers of the second pressure-chamber row are offset with pressure chambers of the first pressure-chamber row in the first direction.

11. The liquid ejection device according to claim 1 , wherein pressure chambers of the third pressure-chamber row are offset with the pressure chambers of the first pressure-chamber row in the first direction, and the pressure chambers of the third pressure-chamber row are offset with the pressure chambers of the second pressure-chamber row in the first direction.

12. A liquid ejection device, comprising:

a first channel member having a pressure chamber A elongated along a longitudinal direction and a pressure chamber B next to the pressure chamber A in the longitudinal direction;

a second channel member disposed next to the first channel member in the longitudinal direction, the second channel member having a pressure chamber C and a pressure chamber D positioned next to the pressure chamber in the longitudinal direction;

a piezoelectric element A and a piezoelectric element B positioned corresponding to the pressure chamber A and the pressure chamber B, respectively, wherein the piezoelectric element B is next to the piezoelectric element A in the longitudinal direction;

a piezoelectric element C and a piezoelectric element D positioned corresponding to the pressure chamber C and the pressure chamber D, respectively, wherein the piezoelectric element D is next to the piezoelectric element C in the longitudinal direction;

a contact A and a contact B connected to the piezoelectric element A and the piezoelectric element B, respectively, the contact A and the contact B positioned at respective outer positions than the piezoelectric element A and the piezoelectric element B from a center of the liquid ejection device in the longitudinal direction; and

a contact C and a contact D connected to the piezoelectric element C and the piezoelectric element D, respectively, the contact C and the contact D positioned at respective outer positions than the piezoelectric element C and the piezoelectric element D from the center of the liquid ejection device in the longitudinal direction.

13. A liquid ejection device comprising:

a first channel member having a plurality of first pressure chambers constituting a first pressure-chamber row and a second pressure-chamber row, wherein the first and second pressure-chamber rows extend along a first direction and the second pressure-chamber row is next to the first pressure-chamber row in a second direction orthogonal to the first direction;

a second channel member positioned next to the first channel member in the second direction, the second channel member having a plurality of second pressure chambers constituting a third pressure-chamber row and a fourth pressure-chamber row, wherein the third and fourth pressure-chamber rows extend along the first direction and the fourth pressure-chamber row is next to the third pressure-chamber row in the second direction;

a plurality of first piezoelectric elements positioned corresponding to the plurality of first pressure chambers, respectively, the plurality of first piezoelectric elements constituting a first piezoelectric-element row and a second piezoelectric-element row, the second piezoelectric-element row is next to the first piezoelectric-element row in the second direction;

a plurality of second piezoelectric elements positioned corresponding to the plurality of second pressure chambers, respectively, the plurality of second piezoelectric elements constituting a third piezoelectric-element row and a fourth piezoelectric-element row, the fourth piezoelectric-element row is next to the third piezoelectric-element row in the second direction;

a plurality of first contacts connected to the plurality of first piezoelectric elements, respectively;

a plurality of second contacts connected to the plurality of second piezoelectric elements, respectively;

wherein the first piezoelectric element row and the second piezoelectric element row are positioned between the plurality of first contacts and the second channel member in the second direction; and

wherein the third piezoelectric element row and the fourth piezoelectric element row are positioned between the plurality of second contacts and the first channel member in the second direction.