Vibrating mirror element

1. A vibrating mirror element comprising:

a mirror portion reflecting light;

a torsionally deformable beam portion not having a driving electrode and connected to said mirror portion for supporting said mirror portion in a vibratile manner; and

a driving portion having a driving electrode for deforming said driving portion and a connecting portion which is provided with said driving electrode and connected with said torsionally deformable beam portion for driving said mirror portion through said torsionally deformable beam portion, wherein

the width of said connecting portion of said driving portion having said driving electrode is rendered smaller than the width of a portion of said driving portion having said driving electrode other than said connecting portion in plan view, and

said beam portion is torsionally deformed by deformation of said driving portion.

2. The vibrating mirror element according to claim 1 , wherein

said connecting portion of said driving portion is formed on an end portion of said driving portion.

3. The vibrating mirror element according to claim 1 , wherein

said beam portion is connected with said driving portion from a direction orthogonal to the longitudinal direction of said driving portion on said connecting portion, and

a side surface of said driving portion opposite to said connecting portion is formed to extend in a direction parallel to the longitudinal direction of said driving portion.

4. The vibrating mirror element according to claim 3 , wherein

a side surface of said driving portion closer to said connecting portion is formed to protrude toward the side of said beam portion in plan view.

5. The vibrating mirror element according to claim 1 , wherein

said beam portion includes a pair of first beam portions having first end portions connected with both sides of said mirror portion respectively and a pair of second beam portions connected with second end portions of said pair of first beam portions respectively,

said driving portion includes a first driving portion having a pair of first connecting portions connected with first end portions of said pair of second beam portions respectively and a second driving portion having a pair of second connecting portions connected with second end portions of said pair of second beam portions respectively, and

the widths of said pair of first connecting portions of said first driving portion are rendered smaller than the width of a portion of said first driving portion other than said pair of first connecting portions respectively, while the widths of said pair of second connecting portions of said second driving portion are rendered smaller than the width of a portion of said second driving portion other than said pair of second connecting portions respectively.

6. The vibrating mirror element according to claim 5 , wherein

said pair of first connecting portions of said first driving portion are formed on both end portions of said first driving portion respectively, while said pair of second connecting portions of said second driving portion are formed on both end portions of said second driving portion respectively.

7. The vibrating mirror element according to claim 5 , wherein

said pair of first beam portions are formed to extend on a straight line passing through the center of said mirror portion toward one side of said mirror portion and toward another side of said mirror portion respectively, and

a side surface of said first driving portion opposite to said connecting portion and a side surface of said second driving portion opposite to said connecting portion are formed to extend in a direction parallel to said straight line passing through the center of said mirror portion respectively.

8. The vibrating mirror element according to claim 1 , further comprising a fixed portion provided in the vicinity of a central portion of said driving portion in the longitudinal direction for constituting a fixed end in vibration of said driving portion, wherein

said driving portion is so formed that the width thereof is gradually reduced from a portion in the vicinity of said fixed portion toward said connecting portion of said driving portion in plan view.

9. The vibrating mirror element according to claim 8 , wherein

said driving portion is so formed that the width thereof is continuously reduced from said portion in the vicinity of said fixed portion toward said connecting portion of said driving portion in plan view.

10. The vibrating mirror element according to claim 9 , wherein

a side surface of said driving portion closer to said connecting portion is formed to linearly extend in a state inclined with respect to the longitudinal direction of said driving portion in plan view.

11. The vibrating mirror element according to claim 8 , wherein

said driving portion is so formed that the width thereof is reduced stepwise from said portion in the vicinity of said fixed portion toward said connecting portion of said driving portion in plan view.

12. The vibrating mirror element according to claim 11 , wherein

a side surface of said driving portion closer to said connecting portion is formed to have a step in plan view.

13. The vibrating mirror element according to claim 8 , wherein

the width of said beam portion is rendered smaller than the width of at least said portion of said driving portion in the vicinity of said fixed portion.

14. The vibrating mirror element according to claim 1 , wherein

said driving portion is formed to be substantially symmetrical to a straight line passing through a substantially central portion of said driving portion in the longitudinal direction and extending in the short-side direction of said driving portion in plan view.

15. The vibrating mirror element according to claim 1 , wherein

said connecting portion of said driving portion is formed as a free end, and

said beam portion connected to said connecting portion of said driving portion is inclined and torsionally deformed by flexural deformation and torsional deformation of said driving portion.

16. The vibrating mirror element according to claim 1 , wherein

said mirror portion and said beam portion are integrally formed.

17. The vibrating mirror element according to claim 16 , wherein

said driving portion includes a movable portion integrally formed with said mirror portion and said beam portion and a driving element formed on the surface of said movable portion.

18. The vibrating mirror element according to claim 1 , wherein

said driving portion includes a movable portion connected with said beam portion and a driving element formed substantially over the entire surface of said movable portion.

19. The vibrating mirror element according to claim 1 , wherein

said driving portion includes a first driving portion connected with a first end portion of said beam portion and driven by application of a voltage and a second driving portion connected with a second end portion of said beam portion and driven by application of a voltage,

said mirror portion and said beam portion are formed to resonate at a prescribed resonance frequency, and

said first driving portion and said second driving portion are formed to be deformed in opposite directions by application of voltages having frequencies substantially identical to said prescribed resonance frequency and having phases reverse to each other respectively.

20. The vibrating mirror element according to claim 1 , further comprising:

an outer beam portion connected to said driving portion and torsionally deformable, and

an outer driving portion having an outer connecting portion connected with said outer beam portion for driving said mirror portion.

21. A vibrating mirror element comprising:

a mirror portion reflecting light;

a torsionally deformable beam portion not having a driving electrode and connected to said mirror portion for supporting said mirror portion in a vibratile manner; and

a driving portion having a driving electrode for deforming said driving portion and a connecting portion which is provided with said driving electrode and connected with said torsionally deformable beam portion for driving said mirror portion through said torsionally deformable beam portion, wherein

the width of said connecting portion of said driving portion having said driving electrode is rendered smaller than the width of a portion of said driving portion having said driving electrode other than said connecting portion in plan view,

said connecting portion of said driving portion is formed on an end portion of said driving portion.