Micromechanical device and method for the two-dimensional deflection of light
AssigneeRobert Bosch GmbH
InventorsMirko Hattass, Robert Maul
Life of this patent
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Abstract
A micromechanical device and a method for the two-dimensional deflection of light. The device includes a mirror unit having a mirror surface for deflecting light striking the mirror surface; the mirror unit being rotatably situated about a first axis within a first frame unit and being fastened to the first frame unit; the first frame unit being rotatably situated about a second axis within an actuator structure and being fastened to the actuator structure; the actuator structure including at least four piezoelectric actuator units; and the positions of the at least four piezoelectric actuator units being situated symmetrically with respect to the first axis and also with respect to the second axis.
Claims24
A micromechanical device for the two-dimensional deflection of light, comprising:
- a first frame unit;
- an actuator structure that includes at least four piezoelectric actuator units;
- and
- a mirror unit that:
- has a mirror surface for deflecting light striking the mirror surface;
- and
- is rotatably situated about a first axis of rotation within, and fastened to, the first frame unit;
- wherein:
- the first frame unit is rotatably situated about a second axis of rotation within, and fastened to, the actuator structure;
- the at least four piezoelectric actuator units are positioned symmetrically both with respect to the first axis and with respect to the second axis;
- and
- any one or more of the following four features (a)-(d):
- (a) a direction in which one of the first and second axes extends is parallel to respective directions in which respective central longitudinal axes of the at least four piezoelectric actuator units extend;
- (b) different ones of the at least four piezoelectric actuator units are simultaneously movable so that their respective central longitudinal axes, which, when the micromechanical device is at rest, all extend along and within a same plane, instead simultaneously extend along and within respective planes, of which at least two are different than each other;
- (c) for each of the at least four piezoelectric actuator units, the respective piezoelectric actuator unit is actuatable by application of voltage between a respective pair of electrodes between which piezoelectric material of the respective piezoelectric actuator unit is arranged;
- and
- (d) the at least four piezoelectric actuator units include first, second, third, and fourth piezoelectric actuator units arranged to:
- respond to application of a first set of voltages by (1) the first and second piezoelectric actuator units shifting in a first direction that is perpendicular to the first and second axes and (2) the third and fourth piezoelectric actuator units shifting in an opposite second direction that is perpendicular to the first and second axes;
- and
- respond to application of a second set of voltages by (1) the second and fourth piezoelectric actuator units shifting in the first direction and (2) the first and third piezoelectric actuator units shifting in the second direction.
A method for the two-dimensional deflection of light using a micromechanical device, the micromechanical device including (a) a first frame unit, (b) an actuator structure that includes at least four piezoelectric actuator units, and (c) a mirror unit that (1) has a mirror surface for deflecting light striking the mirror surface, and (2) is rotatably situated about a first axis within, and fastened to, the first frame unit, the first frame unit being rotatably situated about a second axis within, and fastened to, the actuator structure, wherein the at least four piezoelectric actuator units are positioned symmetrically both with respect to the first axis and with respect to the second axis, the method comprising:
- applying a first periodic voltage signal to a first piezoelectric actuator unit of the at least four piezoelectric actuator units;
- and
- applying a second periodic voltage signal to a second piezoelectric actuator unit of the at least four piezoelectric actuator units;
- wherein:
- the first and second voltage signals are applied in such a way that an instantaneous amplitude of the second voltage signal is either equal to an instantaneous amplitude of the first voltage signal or is equal to the instantaneous amplitude of the first voltage signal multiplied by minus one;
- and
- the application of the first and second voltage signals shifts the first and second piezoelectric actuator units in same or different ones of at least one of a first direction that is perpendicular to the first and second axes and an opposite second direction that is perpendicular to the first and second axes.
A micromechanical device for two-dimensional deflection of light, the device comprising:
- a first frame unit;
- an actuator structure that includes at least four piezoelectric actuator units;
- and
- a mirror unit that:
- has a mirror surface for deflecting light striking the mirror surface;
- and
- is rotatably situated about a first axis of rotation within, and fastened to, the first frame unit;
- wherein:
- the first frame unit is rotatably situated about a second axis of rotation within, and fastened to, the actuator structure;
- the at least four piezoelectric actuator units are positioned symmetrically both with respect to the first axis and with respect to the second axis;
- the actuator structure includes free longitudinal ends;
- and
- any one or more of the following three features (a)-(c):
- (a) the actuator structure includes two U-shaped sections, each having two of the free ends;
- (b) each of the piezoelectric actuator units is arranged with a respective end of the respective piezoelectric actuator unit at a different respective one of the free longitudinal ends that those of the each of the other ones of the piezoelectric actuator units;
- and
- (c) for respective pairs of adjacent ones of the free longitudinal ends, the first axis extends between the free longitudinal ends of the respective pair.
Dependencies are inferred from the claim text.