Suction device

1. A hand-held suction device having:

a housing having a grip portion on an outer surface of the housing, the housing having an elongated shape with a major longitudinal axis and minor lateral axes that are orthogonal to the major longitudinal axis, the grip portion extending in a longitudinal direction of the housing,

a suction port providing fluid communication between an outside and an inside of the housing, the suction port disposed on a distal end of the housing for drawing fluid into the housing,

a flow passage located in the housing and communicating with the suction port, and

a piezoelectric driving unit comprising:

a plate-like structure having a discharge port located in the housing and communicating with the flow passage,

a top plate having an opening facing the discharge port,

a vibrating plate facing the opening and the discharge port, a pump chamber located along a part of the flow passage in the housing, the pump chamber formed by the top plate and the vibrating plate, and communicating with the flow passage at the opening, and

a piezoelectric element attached to one principal surface of the vibrating plate to displace the vibrating plate, wherein a negative pressure is generated in the pump chamber to suck fluid from the opening by increasing a volume of the pump chamber, and the fluid sucked from the opening is discharged through the opening and the discharge port by reducing the volume of the pump chamber,

wherein a space between the top plate and the plate-like structure is a part of the flow passage,

wherein discharging fluid through the discharge port causes fluid to flow from the suction port to the discharge port,

wherein a direction of movement of the one principal surface and another principal surface of the vibrating plate is not aligned with a longitudinal axis of the suction port, and

wherein the grip portion is located on a portion of the housing opposed to the piezoelectric driving unit.

2. The hand-held suction device according to claim 1 , wherein a longitudinal axis of the discharge port is not aligned with the longitudinal axis of the suction port.

3. The hand-held suction device according to claim 1 , wherein the direction of movement of the one principal surface or the another principal surface of the vibrating plate is not aligned with a longitudinal axis of the discharge port.

4. The hand-held suction device according to claim 1 , wherein the direction of movement of the one principal surface and the another principal surface of the vibrating plate is substantially orthogonal to the longitudinal axis of the suction port.

5. The hand-held suction device according to claim 1 , further comprising:

a circuit board applying a driving voltage to the piezoelectric element,

wherein the one principal surface or the another principal surface of the vibrating plate faces in a direction in which the circuit board is located.

6. The hand-held suction device according to claim 1 , further comprising a shielding plate, wherein the one principal surface or the another principal surface of the vibrating plate faces in a direction in which the shielding plate is located.

7. The hand-held suction device according to claim 1 , wherein the grip portion is at a position opposed to the one principal surface and the another principal surface of the vibrating plate.

8. The hand-held suction device according to claim 7 , wherein a size of the vibrating plate in an in-plane direction of the principal surfaces is larger than a size of an internal space of the housing in a direction in which the one principal surface and the another principal surface of the vibrating plate face.

9. The hand-held suction device according to claim 2 , wherein the direction of movement of the one principal surface or the another principal surface of the vibrating plate aligns with the longitudinal axis of the discharge port.

10. The hand-held suction device according to claim 2 , wherein the direction of movement of the one principal surface and the another principal surface of the vibrating plate is substantially orthogonal to the longitudinal axis of the suction port.

11. The hand-held suction device according to claim 3 , wherein the direction of movement of the one principal surface and the another principal surface of the vibrating plate is substantially orthogonal to the longitudinal axis of the suction port.

12. The hand-held suction device according to claim 2 , further comprising:

a circuit board applying a driving voltage to the piezoelectric element,

wherein the one principal surface or the another principal surface of the vibrating plate faces in a direction in which the circuit board is located.

13. The hand-held suction device according to claim 3 , further comprising:

a circuit board applying a driving voltage to the piezoelectric element,

wherein the one principal surface or the another principal surface of the vibrating plate faces in a direction in which the circuit board is located.

14. The hand-held suction device according to claim 4 , further comprising:

a circuit board applying a driving voltage to the piezoelectric element,

wherein the one principal surface or the another principal surface of the vibrating plate faces in a direction in which the circuit board is located.

15. The hand-held suction device according to claim 2 , further comprising a shielding plate, wherein the one principal surface or the another principal surface of the vibrating plate faces in a direction in which the shielding plate is located.

16. The hand-held suction device according to claim 3 , further comprising a shielding plate, wherein the one principal surface or the another principal surface of the vibrating plate faces in a direction in which the shielding plate is located.

17. The hand-held suction device according to claim 4 , further comprising a shielding plate, wherein the one principal surface or the another principal surface of the vibrating plate faces in a direction in which the shielding plate is located.

18. The hand-held suction device according to claim 5 , further comprising a shielding plate, wherein the one principal surface or the another principal surface of the vibrating plate faces in a direction in which the shielding plate is located.

19. The hand-held suction device according to claim 2 , wherein the grip portion is at a position opposed to the one principal surface and the another principal surface of the vibrating plate.

20. The hand-held suction device according to claim 3 , wherein the grip portion is at a position opposed to the one principal surface and the another principal surface of the vibrating plate.