Low voltage micro-mirror array light beam switch

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION FIG.
1a discloses a sample array of 16 micro-mirrors 6 with actuators 1a on silicon substrate 5.
FIG.
1b is an isometric view of the array of FIG.
1a.
FIG.
1c is a top view of a single mirror 6, controlled by four actuators 1a.
A small fixed portion of each actuator is attached to the substrate 7 for anchoring, such that a cantilever structure like a diving board is created.
Movable end portions of each actuator are flexibly coupled to the central mirror support via narrow flexible tabs, functioning as hinging areas 4 of the support sheet.
See also tab portions 4 in FIG.
9.
The hinging areas reduce potentially damaging actuator stress concentrations.
FIG.
1d is an isometric view of single mirror element 6.
The actual reflective mirror surface is located underneath the central square structure 6a such that the light source emits an upward light beam through the defined areas in the silicon substrate 7 and is reflected by the reflective mirror surface.
Again, each actuator, composed of a PZT capacitor 1a is anchored to the substrate 7 as shown at 7a.
FIG.
1 below shows a cross section A--A taken through FIG.
1c of the optical switch.
The support material of substrate 7 of FIG.
1, provides mechanical support for both the PZT actuators 1a and mirror (6).
The PZT actuators comprise unimorph or bimorph thin film PZT layer 2 sandwiched between upper electrode 1 and lower electrode 3 and form the cantilever structures above the thin movable support sheet member (5).
Several PZT capacitors also can be stacked to create the actuator as shown in FIG.
15.
The mirror (6) is deposited on the underside of the easily flexed support sheet (5).
Aforesaid hinge portions shaped as narrow tabs (4) are advantageously just areas within the support material located between the PZT actuators 1a and the mirror section 6, rather than discreet hinge devices.
Thus the hinges areas are integral with the flexing support sheet (5) and are sufficiently thin and hence flexible so as to act as stress relieving hinge flexing areas, relieving stress from the stiffer actuators