Granted Patent B2

US 7,751,135 · App. 11/999,254 · Granted Jul 6, 2010

Abstract

Claims (31)

1. An apparatus, comprising:

a first lens,

a second lens, and

a piezoelectric element configured to bend in response to a voltage applied thereto, wherein said piezoelectric element is sandwiched between said first lens and said second lens and wherein said first lens, said second lens, and said piezoelectric element are arranged so that said bending causes at least one of said first lens and said second lens to move in at least one movement direction, thus causing movement of at least one of said first lens and said second lens relative to a respective other lens of said first lens and said second lens.

2. The apparatus of claim 1 , wherein said piezoelectric element comprises two layers, and wherein a bending direction of said piezoelectric element is substantially perpendicular to a contact area of both layers.

3. The apparatus of claim 2 , wherein said piezoelectric element comprises a bimorph.

4. The apparatus of claim 2 , wherein said piezoelectric element, said first lens, and said second lens are arranged so that said at least one movement direction is substantially parallel to said bending direction of said piezoelectric element.

5. The apparatus of claim 4 , wherein said piezoelectric element is a substantially plane element that is configured to bend maximally at its center.

6. The apparatus of claim 5 , wherein said piezoelectric element, said first lens, and said second lens are arranged in a way so that the optical axis of said first lens and said second lens substantially goes through said center of said piezoelectric element.

7. The apparatus of claim 1 , wherein said first lens, said second lens, and said piezoelectric element are contained in an at least partially laterally surrounding frame structure and are supported to allow movement of at least one of said first lens and said second lens in the direction of the optical axis of said first lens and said second lens.

8. The apparatus of claim 1 , wherein said piezoelectric element is at least partially arranged in an optical path of said apparatus.

9. The apparatus of claim 8 , wherein said piezoelectric element is at least partially transparent.

10. The apparatus of claim 9 , wherein said piezoelectric element is made of Polyvinylidene Difluoride.

11. The apparatus of claim 9 , wherein said piezoelectric element has at least partially transparent conductive coatings.

12. The apparatus of claim 8 , wherein said piezoelectric element comprises at least one aperture or recess to at least partially avoid blocking of said optical path of said apparatus.

13. The apparatus of claim 1 , further comprising a return element that is configured to exert a return force on at least said at least one of said first lens and said second lens that is caused to move in said at least one movement direction by said bending of said piezoelectric element if said at least one of said first lens and said second lens is moved in said at least one movement direction.

14. The apparatus of claim 13 , wherein said return element is a spring.

15. The apparatus of claim 13 , wherein said return element is a piezoelectric element.

16. The apparatus of claim 15 , wherein said piezoelectric element and said return element work in a push-pull mode.

17. The apparatus of claim 1 , wherein a position of at least said at least one of said first lens and said second lens that is caused to move in said at least one movement direction by said bending of said piezoelectric element is determined by measuring a voltage across said piezoelectric element.

18. The apparatus of claim 1 , further comprising a step-up, switch-mode supply configured to provide a high voltage to said piezoelectric element.

19. The apparatus of claim 1 , wherein said apparatus is embodied as a module.

20. The apparatus of claim 1 , wherein said apparatus is comprised in a device that is capable of capturing images.

21. The apparatus of claim 1 , wherein said apparatus is comprised in a camera.

22. The apparatus of claim 1 , wherein said apparatus is comprised in a mobile phone.

23. A method, comprising:

applying a voltage to a piezoelectric element to cause said piezoelectric element to bend, wherein said piezoelectric element is sandwiched between a first lens and a second lens and wherein said piezoelectric element, said first lens, and said second lens are arranged so that said bending causes at least one of said first lens and said second lens to move in at least one movement direction, thus causing movement of at least one of said first lens and said second lens relative to the respective other lens of said first lens and said second lens.

24. The method of claim 23 , wherein said piezoelectric element is extended in at least one direction, and wherein a bending direction of said piezoelectric element is substantially perpendicular to said at least one direction in which said piezoelectric element is extended.

25. A computer-readable medium having a computer program stored thereon, the computer program comprising:

instructions operable to cause a processor to apply a voltage to a piezoelectric element to cause said piezoelectric element to bend, wherein said piezoelectric element is sandwiched between a first lens and a second lens and wherein said piezoelectric element, said first lens and said second lens are arranged so that said bending causes at least one of said first lens and said second lens to move in at least one movement direction, thus causing movement of at least one of said first lens and said second lens relative to the respective other lens of said first lens and said second lens.

26. The computer-readable medium of claim 25 , wherein said piezoelectric element is extended in at least one direction, and wherein a bending direction of said piezoelectric element is substantially perpendicular to said at least one direction in which said piezoelectric element is extended.

Assignments (6)