Actuator for a printhead
An actuator ( 1 ) comprising: an actuating element ( 2 ); a first mounting ( 3 ) and a second mounting ( 4 ), configured for allowing the actuating element ( 2 ) to be positioned on a reference plane (P); characterized in that: the first mounting ( 3 ) is operable to allow the actuating element ( 2 ) to move in a direction (X) substantially parallel to the reference plane (P) and to allow a portion of a first end of the actuating element ( 2 ) to rotate about a first axis of rotation (T) substantially perpendicular to (X), thereby minimising wear between the actuating element ( 2 ) and the first mounting ( 3 ) during actuation.
1. An actuator ( 1 ) for a printhead comprising:
a piezoelectric actuator element ( 2 ) made of piezoelectric material;
a first mounting ( 3 ) and a second mounting ( 4 ), configured for allowing the piezoelectric actuator element ( 2 ) to be positioned on a reference plane (P); characterized in that:
the piezoelectric actuator element ( 2 ) has a first surface and an opposite second surface;
the first mounting ( 3 ) is operable to allow the piezoelectric actuator element ( 2 ) to move in a direction (X) substantially parallel to the reference plane (P) and to allow a portion of a first end of the piezoelectric actuator element ( 2 ) to rotate about a first axis of rotation (T) substantially perpendicular to the direction (X); wherein the second mounting ( 4 ) comprises an elastic element in contact with the first surface of the piezoelectric actuator element ( 2 ), the elastic element exerting a biasing force on the first surface of the piezoelectric actuator element ( 2 ) which biases the piezoelectric actuator element ( 2 ) in a direction towards the reference plane (P).
2. The actuator ( 1 ) according to claim 1 wherein the piezoelectric actuator element ( 2 ) has an elongated structure.
3. The actuator according to claim 1 , wherein the second mounting ( 4 ) is configured to allow a portion of a second end of the piezoelectric actuator element ( 2 ) to rotate about a second axis of rotation (R) substantially perpendicular to the direction (X) and parallel to the first axis of rotation (T).
4. The actuator ( 1 ) according to claim 3 , wherein the second mounting ( 4 ) comprises a surface of substantially arched shape ( 6 ), arranged to maintain the piezoelectric actuator element ( 2 ) on the reference plane (P) and structured to allow the piezoelectric actuator element ( 2 ) to rotate about the second axis of rotation (R).
5. The actuator ( 1 ) according to claim 4 , wherein the first mounting ( 3 ) comprises a roller ( 5 ) having a central axis, operable to rotate about the first axis of rotation (T); and wherein said piezoelectric actuator element ( 2 ) is operable to roll without scraping on said roller ( 5 ) of said first mounting ( 3 ) and to roll without scraping on said surface of substantially arched shape ( 6 ) of said second mounting ( 4 ).
6. The actuator ( 1 ) according to claim 4 , wherein the elastic element presses the piezoelectric actuator element ( 2 ) into contact with said surface of substantially arched shape ( 6 ).
7. The actuator ( 1 ) according to claim 6 , wherein said elastic element is made at least partly of an elastomeric material.
8. The actuator ( 1 ) according to claim 6 , wherein the second mounting ( 4 ) comprises a stop surface ( 6 a ), operable to allow the piezoelectric actuator element ( 2 ) to be positioned along the direction (X).
9. The actuator ( 1 ) according to claim 8 , wherein said second mounting ( 4 ) comprises a space ( 7 ) configured for housing inside it at least one end portion of the first or second end of said piezoelectric actuator element ( 2 ) during its said rotation about the second axis of rotation (R).
10. The actuator ( 1 ) according to claim 1 , wherein the first mounting ( 3 ) comprises a roller ( 5 ) having a central axis, operable to rotate about the first axis of rotation (T).
11. The actuator ( 1 ) according to claim 10 , wherein the central axis of the roller ( 5 ) is spaced apart from the reference plane (P).
12. The actuator ( 1 ) according to claim 10 , wherein the roller ( 5 ) is configured for rolling in a direction parallel to the direction (X).
13. The actuator ( 1 ) according to claim 10 , wherein the roller ( 5 ) is locatable in a groove ( 49 ) which extends along a direction parallel to the first axis of rotation (T), said groove ( 49 ) being elongated in a direction perpendicular to the direction (X).
14. The actuator ( 1 ) according to claim 10 , wherein the first mounting ( 3 ) comprises a second elastic element configured to exert a force on the piezoelectric actuator element ( 2 ) which presses the piezoelectric actuator element ( 2 ) into contact with the roller ( 5 ).
15. The actuator ( 1 ) according to claim 14 , wherein said second elastic element is made at least partially of an elastomeric material.
16. A printhead having at least one actuator ( 1 ) as claimed in claim 1 .
17. A printer having at least one printhead as claimed in claim 16 .
18. A printer having at least one actuator ( 1 ) as claimed in claim 1 .
19. A method of inkjet printing on a substrate, the method comprising using the printer of claim 18 to deposit a fluid on the substrate.