Mirror device
In order to expand the surface area of a reflective layer, the space between adjacent turns of a drive coil, which is wound a plurality of turns on a peripheral edge front surface of the principal surface of a movable portion which, being inside a frame-formed support substrate, is connected to the support substrate by torsion bars, is filled and flattened with a smoothing layer, thereby adopting a configuration such that the reflective layer can also be provided in the region of the upper surface of the drive coil.
1. A mirror device, comprising:
a support substrate of a frame form;
a movable portion which is provided inside the frame form of the support substrate;
first torsion bars which, being provided between the support substrate and the movable portion, connect the movable portion to the support substrate;
a first drive coil which is wound a plurality of turns on the peripheral edge of the principal surface of the movable portion;
a smoothing layer which, being different from the movable portion and provided on the front surface of the movable portion including the first drive coil, fills the space between adjacent turns of the first drive coil and covers an upper surface of the first drive coil, flattening the front surface of the movable portion; and
a reflective layer which, being provided on the front surface of the smoothing layer, reflects light.
2. The mirror device according to claim 1 , wherein
the reflective layer is provided in a region of the front surface of the movable portion excluding stress concentration portions of the connections between the movable portion and the first torsion bars.
3. The mirror device according to claim 1 , wherein
slits are provided in the stress concentration portions of the connections of the movable portion to the first torsion bars.
4. The mirror device according to claim 1 , wherein
slits are provided in the stress concentration portions of the first torsion bars.
5. The mirror device according to claim 1 , wherein
a covering layer lower in light reflectance than the reflective layer is provided on the front surface of the support substrate.
6. The mirror device according to claim 5 , wherein
the light reflectance of the covering layer is lower than the reflectance of a component covered with the covering layer.
7. The mirror device according to claim 5 , wherein
the covering layer is provided in a region of the front surface of the movable portion excluding the stress concentration portions of the connections between the movable portion and the first torsion bars.
8. The mirror device according to claim 1 , wherein
an embedded member is provided in the front surface of the movable portion, and the front surface of the movable portion including the embedded member is flattened by the smoothing layer.
9. The mirror device according to claim 1 , wherein
one or more lightening portions exist in a surface of the movable portion opposite to the surface thereof on which the reflective layer is provided.
10. The mirror device according to claim 1 , wherein
the support substrate is configured of an intermediate frame which supports the movable portion and an outside frame provided outside the intermediate frame, wherein the intermediate frame and the outside frame are connected together by second torsion bars oriented in a direction perpendicular to the first torsion bars, and a second drive coil is wound a plurality of turns on the peripheral edge of the principal surface of the intermediate frame.
11. The mirror device according to claim 10 , wherein
a covering layer lower in light reflectance than the reflective layer is provided on at least one of the respective front surfaces of the intermediate and outside frames.
12. The mirror device according to claim 11 , wherein
the covering layer is provided in a region of the front surface of the intermediate frame excluding the stress concentration portions of the connections between the intermediate frame and the first torsion bars.
13. The mirror device according to claim 11 , wherein
slits are provided in at least either the stress concentration portions of the connections between the intermediate frame and the second torsion bars or the stress concentration portions of the connections between the outside frame and the second torsion bars.
14. The mirror device according to claim 11 , wherein
slits are provided in the stress concentration portions of the second torsion bars.
15. The mirror device according to claim 10 , wherein
one or more lightening portions exist in a surface of the intermediate frame opposite to the surface thereof on which the reflective layer is provided.