Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
  • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
  • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
  • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
  • G02B26/0841—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD the reflecting element being moved or deformed by electrostatic means
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
  • G02B7/18—Mountings, adjusting means, or light-tight connections, for optical elements for prisms; for mirrors
  • G02B7/182—Mountings, adjusting means, or light-tight connections, for optical elements for prisms; for mirrors for mirrors
  • G02B7/1821—Mountings, adjusting means, or light-tight connections, for optical elements for prisms; for mirrors for mirrors for rotating or oscillating mirrors

Definitions

• This invention relates generally to micro-machined three-dimensional structures, and in particular to micro-machined mirrors for use in optical readers, such as bar code readers or scanners.
• Conventional bar code scanners are used to scan a surface with a laser beam.
• Conventional bar code scanners further typically utilize mirrors that are oscillated to permit the laser beam to scan.
• Conventional mirrors for bar code scanners are relatively large and imprecise.
• micro-machining processes have been used in which a silicon substrate is micro-machined to produce a mirror.
• conventional micro-machined mirrors and their manufacturing processes suffer from a number of limitations.
• Prior art micro-machined mirrors do not provide appropriate compliance in all directions of the movement of the mirror. Such mirrors typically are not sufficiently shock resistant or able to operate over wide ranges of temperature over extended use.
• the present invention provides micro-machined mirror devices which overcome one or more limitations of the existing micro-machined devices. Summary of the Invention
• a mirror assembly includes a mirror, a top cap, and a bottom cap.
• the mirror includes a mirror support structure, a pair of T-shaped hinges coupled to the mirror support structure and a mirrored plate coupled to the T-shaped hinges.
• the mirrored plate includes one or more travel stops for limiting movement of the mirrored plate.
• the top cap is coupled to the top side of the mirror.
• the top cap includes a top cap support structure that includes an opening for permitting light to reflect off of the mirrored plate and one or more travel stops coupled to the top cap support structure for limiting movement of the mirrored plate.
• the bottom cap is coupled to the bottom side of the mirror.
• the bottom cap includes a bottom cap support structure including an opening and one or more travel stops coupled to the bottom cap support structure for limiting movement of the mirrored plate.
• a mirror assembly is provided that includes a support structure, pair of T-shaped hinges coupled to the support structure and a mirrored plate coupled to the T- shaped hinges.
• the mirrored plate includes one or more travel stops for limiting movement of the mirrored plate.
• an apparatus includes a housing, a mass, and one or more springs for coupling the mass to the housing.
• Each spring includes a rotational spring constant and a translational spring constant.
• the rotational spring constant is decoupled from the translational spring constant.
• a method of resiliently supporting a mass in a housing includes coupling the mass to the housing using one or more hinges having translational spring constants and rotational spring constants and decoupling the translational spring constants from the rotational spring constants.
• a method of resiliently supporting a mass in a housing includes limiting translational movement of the mass in the X, Y and Z directions and limiting rotational or torsional movement of the mass.
• an apparatus is provided that includes a housing and a mass resiliently coupled to the housing.
• the mass includes one or more travel stops for limiting rotational and translational or planar movement of the mass.
• a method of reflecting rays of light includes a reflective surface and providing an optical pathway for accessing the reflective surface or planar one or more cutouts for minimizing clipping of the incident and reflected light rays.
• FIG. 1 is a cross section view of a laser scanning device according to the present invention.
• FIG. 2 is a schematic side view of a preferred embodiment of the
• FIG. 3 is a top view of the top cap of the mirror assembly of FIG. 2.
• FIG. 4 is a cross-sectional view of the top cap of FIG.3.
• FIG. 5 is a cross-sectional view of the top cap of FIG. 3.
• FIG. 6 is a top view of the mirror of the mirror assembly of FIG. 2.
• FIG. 6A is a top view of an alternative embodiment of the hinge of the
• FIG. 6B is a top view of an alternative embodiment of the hinge of the
• FIG. 6C is a top view of an alternative embodiment of the hinge of the
• FIG. 6D is a top view of an alternative embodiment of the mirror of the
• FIG. 7 is a cross-sectional view of the mirror of FIG. 6.
• FIG. 8 is a cross-sectional view of the mirror of FIG. 6.
• FIG. 9 is a bottom view of the mirror of FIG. 6.
• FIG. 10 is a top view of the bottom cap of the mirror assembly of FIG.
• FIG. 11 is a cross-sectional view of the bottom cap of FIG. 10.
• FIG. 12 is a cross-sectional view of the bottom cap of FIG. 10.
• FIG. 13 is a top view of the base member of the mirror assembly of
• FIG. 14 is a cross-sectional view of the base member of FIG. 13.
• FIG. 15 is a cross-sectional view of the base member of FIG. 13.
• FIG. 16 is a top view of the top cap and mirror of the mirror assembly
• FIG. 17 is a top view of the bottom cap and base member of the mirror assembly of FIG. 2.
• FIG. 18 is a cross-sectional view of the mirror assembly of FIG. 16 illustrating the oscillation of the mirror collection plate.
• FIG. 19 is a view of the mirror assembly of FIG. 18 illustrating the use of tapered surfaces to minimize clipping of the laser light.
• the mirror assembly for use in a bar code reader is provided.
• the mirror assembly preferably includes a micro-machined three-dimensional mirror supported generally by a pair of "T" shaped hinges in a support structure.
• the mirror assembly further preferably includes one or more travel stops for limiting the movement of the mirror.
• the mirror assembly further preferably includes one or more tapered edge surfaces and cut-outs for minimizing clipping of incident and reflected laser beams.
• FIG. 1 is a cross section view of a laser scanning device such as a bar
• the light beam is reflected or scattered by the target 120.
• the bar code scanner 100 includes a laser beam source 105 and a mirror assembly 110. During the operation of the bar code scanner 100, the
• optically reflective portion 111 of the mirror assembly 110 is preferably
• the reflected light 125 enters the bar code scanner 100 through a window 165 and is detected by a light detector
• the laser beam source 105 may comprise any number of conventional
• the bar code scanner 100 may include additional features for user interface, control and data processing. These features may comprise a processor 130 and memory device 135 as part of a central processing unit
• a controller 145 for generating voltage used to oscillate the mirror 110 a controller 145 for generating voltage used to oscillate the mirror 110, a
• a data entry device such as a keypad 150 and a data display device such as a
• liquid crystal display 155 The mirror assembly 110 made according to the present invention is described below in reference to FIGS. 2-19.
• the mirror assembly in a preferred embodiment, the mirror assembly
• top cap 205 includes a top cap 205, a mirror 210, a bottom cap 215, and a base
• the top cap 205 includes an opening that permits the laser
• the mirror 210 is surrounded and protected by the top cap 205 and the bottom cap 215.
• the top cap 205 and bottom cap 215 may be fabricated from any number of conventional commercially available materials such as, for example, silicon glass, ceramic or plastic. In a preferred embodiment, the top cap 205 is fabricated by micro-machining a silicon wafer.
• FIGS. 3-5 show various views of a preferred embodiment of the top
• cap 205 which has a frame 301 that includes a top, bottom, left and right
• Top and bottom travel stop members 310 and 320 are coupled respectively to the top and bottom support members 305 and 315.
• the top cap frame 301 provides an overall support structure for the top
• the thickness of the frame 301 may range, for example, from about 400 to 600 microns with a preferred thickness ranging from about 390 to 400 microns in order to provide a compact structure having a low mass.
• the top travel stop 310 preferably limits the motion of the reflective
• the top travel stop 310 preferably extends in substantially orthogonal direction from the top support member 305. In a preferred embodiment, the top travel stop 310 is positioned within the plane of the top support member 305. The thickness of the top travel stop
• 310 may range, for example, from about 340 to 580 microns. In a preferred
• the thickness of the top travel stop 310 ranges from about 350 to 380 microns in order to provide optimum shock protection, freedom of motion, and a compact structure having a low mass.
• bottom surface 310b of the top travel stop 310 is preferably positioned above
• the length of the top travel stop member 310 may range, for example, from about 800 to 2800 microns. In a preferred embodiment, the length of the top travel stop member 310 ranges from about 2000 to 2500 microns. In a particularly preferred
• the length of the top travel stop member 310 is selected to overlap with the mirror collection plate 610 of the mirror by about 300 microns.
• the bottom travel stop 320 extends in a substantially orthogonal direction from the bottom support member 315 and is substantially identical to
• An opening 345 permits light to reflect off of the reflective surface of the mirror 210.
• the opening 345 preferably includes a
• left rim cut out 330 and a right rim cut out 340 The left and right rim cut outs
• 330 and 340 are preferably positioned on opposite sides in surrounding
• right rim cut-outs, 330 and 340 provide optical access to the reflective surface of the mirror 210.
• the top cap frame 301 , travel stops 310 and 320, rim cut outs 330 and 340, and the opening 345 all include tapered
• edges, 350A and 350B to facilitate optical access to the reflective surface of
• 350B preferably ranges from about 50 to 60 degrees in order to optimally facilitate the reflection of laser light transmitted at an angle towards the edge portions of the reflective surface of the mirror 210.
• FIG. 6 shows a top view of a mirror or mirror assembly 210 made
• the mirror 210 is a mirror 210 .
• the mirror 210 includes a frame or mirror support structure 600 having support members 602, 604, 606 and 608.
• the mirror 210 further comprises a mirror collection
• the mirror frame 600 provides the overall support structure for the mirror 210.
• the thickness of the frame 600 may range, for example, from about 400 to 600 microns with a preferred thickness ranging from about 400 to 450 microns in order to provide a compact structure having a low mass.
• the support members 602, 604, 606, and 608 provide effective beam lengths ranging from about 500-2500 microns and cross sections of about 8,000 microns 2 to 160,000 microns 2 in order to optimally absorb shock loads of about 2000g/0.5 mS half sine wave input.
• the mirror collection plate 610 is coupled to the top T-shaped hinge
• the axis 630 is positioned substantially along the centerline of the mirror collection plate 610 and is coincident with the center of the T-shaped hinges, 612 and 614, thereby providing a common
• the reflective surface 628 is coupled to the
• mirror collection plate 610 about the axis 630 causes laser light from a
• the thickness of the mirror collection plate 610 may range, for example, from about 100 to 600 microns with a preferred thickness ranging from about 100 to 250 microns to provide a low mass and maximize the effective natural frequency of the mirror 210.
• the reflective surface 628 may be comprised of any number of conventional commercially available optically reflective surfaces such as, for example, gold, silver or aluminum.
• the reflective surface 628 comprises gold in order to optimize the amount of optical energy that is reflected.
• the surface roughness of the reflective surface 628 is less than about 0.1 wavelengths of the reflected light in order to optimize the amount of optical energy that is reflected.
• FIGS. 7 and 8 show cross-sectional views of the mirror of FIG. 6 and FIG. 9 shows a bottom view of the mirror of FIG. 6. As illustrated in
• FIGS. 7-9 in a preferred embodiment, the bottom 634 of the mirror collection
• top travel stop 710 includes a top travel stop 710, a bottom travel stop 715, and a
• the top travel stop 710 extends from the bottom 634 of the
• the top travel stop 710 preferably limits movement of the mirror collection plate 610 in the z-direction.
• stop 710 preferably extends from the bottom 634 of the mirror collection
• the top travel stop 710 may
• the top travel stop 710 is centered about the axis 630 and is positioned adjacent to and on
• the bottom travel stop 715 is preferably identical
• the cavity 720 extends into the bottom of the mirror collection plate 610, which reduces the mass of the mirror collection plate 610. In this manner, the droop of the mirror 210 is reduced.
• the cavity 720 extends into the bottom of the mirror collection plate 610, which reduces the mass of the mirror collection plate 610. In this manner, the droop of the mirror 210 is reduced.
• the depth and volume of the cavity 720 ranges from about 200 to 500 microns and 8X10 6 to 1X10 9 microns. 3
• the cavity 720 is centrally positioned along the axis 630 and within the back side
• the rotational accuracy of the laser beam may be required to be within 1.3° when the mirror collection plate 610 is subjected to an across-the-hinge self-induced gravity torque.
• torque T mg*h/2
• mg mirror collection plate weight
• h mirror collection plate thickness.
• the mirror accuracy is a function of the pointing accuracy and mirror droop.
• the torsional spring constant K r of the T-shaped hinges, 612 and 614, is determined by the resonant frequency F of
• the mirror collection plate 610 and the size and mass of the mirror collection
• the thickness and mass of the mirror collection plate 610 are preferably selected to provide a mirror tilt angle less than 1.3°. In a preferred embodiment, the thickness and mass of the mirror collection plate 610 are reduced by reducing the thickness of the mirror collection plate 610 and by providing one or more cavities in the mirror collection plate 610.
• the top T-shaped hinge 612 is coupled to the left support member 606, the right support member 608, and the top portion of the mirror
• the top T-shaped hinge 612 preferably includes a vertical support member 644 (beam or leg) and a second or horizontal support member 646 (T-member).
• the horizontal support member 646 preferably is supported at opposite ends by the left support member 606 and the right support member 608. In a preferred embodiment, the horizontal
• support member 646 is substantially orthogonal to both the left support
• the vertical support member 644 is substantially orthogonal to the horizontal support member 646.
• the vertical support member 644 is positioned along the axis 630.
• the length, width and thickness of the vertical support member 644 may range, for example, from about 100 to 2500 microns, 2 to 100 microns and 2 to 100 microns, respectively. In a preferred embodiment, the length, width and thickness of the vertical support member 644 range from about 800 to 1000 microns, 8 to 15 microns and 8 to 15 microns, respectively.
• the torsional spring constant of the vertical support member 644 may range, for example, from about 2x10 "9 to 10x10 "7 Ibf-ft/radian. In a preferred embodiment, the torsional spring constant of the vertical support member 644 ranges from about 2x10 "8 to 10x10 8 Ibf-ft/radian.
• the length, width and thickness of the horizontal support member 646 may range, for example, from about 500 to 4500 microns, 6 to 100 microns and 6 to 100 microns, respectively. In a preferred embodiment, the length, width and thickness of the horizontal support member 646 range from about 2200 to 2500 microns, 15 to 25 microns and 15 to 25 microns, respectively.
• the bottom T-shaped hinge 614 is coupled to the left support member 606, the right support member 608, and the bottom portion of the mirror collection plate 610.
• the bottom T-shaped hinge 614 has the same
• FIGS. 6A-6C Other embodiments of a T-shaped hinge according to the present invention, as illustrated in FIGS. 6A-6C, provide enhanced sensitivity for
• a vertical support member 644A having a serpentine shape and a
• an alternative embodiment of a T-shaped hinge 612B includes a vertical support member 644B coupled to a horizontal support member 646B at
• T-shaped hinge 612C having a vertical support member 644C that intersects a horizontal support member
• the top left travel stop 616 extends from and is coupled to the top left
• the top left travel stop 616 preferably limits the motion of the mirror collection plate 610 in the x- direction.
• the top left travel stop 616 preferably is positioned in the plane of
• the top left travel stop 616 extends from the mirror collection plate 610 in a substantially
• the thickness of the top left travel stop 616 may range, for example, from about 200 to 600 microns. In a preferred embodiment, the thickness of the top left travel stop 616 ranges from about 250 to 350 microns in order to optimally provide shock protection, and a resilient compact structure having a low mass.
• the length of the top left travel stop 616 may range, for example, from about 500 to 2000 microns. In a preferred
• the length of the top left travel stop 616 ranges from about 900 to 1100 microns.
• the top surface of the top left travel stop 616 is planar with the top surface of the mirror collection plate 610.
• top left travel stop 616 is planar with the bottom surface of the top left travel stop 616
• top left travel stop 616 are substantially identical to the top left travel stop 616. These travel stops are positioned in corresponding locations about the mirror collection plate 610.
• the travel stops, 616, 618, 620 and 622 preferably provide overswing and x-axis shock protection for the mirror collection plate 610 during manufacturing and operation.
• the travel stops 616, 618, 620, and 622 are formed as integral parts of the mirror collection plate 610.
• the travel stops 616, 618, 620, and 622 provide effective beam lengths greater than about 500 microns and cross sections of about 40,000 microns 2 to 240,000 microns 2 in order to optimally absorb shock loads of about 2000g/0.5 mS half sine wave input.
• the opening 624 preferably permits the mirror collection plate 610 to
• the walls 636 of the opening 624 preferably limit movement of the mirror collection plate 610 in the x-direction and the y- directions.
• the opening 624 preferably includes a top section 638, a middle section 640, and a bottom section 642.
• top T-shaped hinge 612 preferably contains the top T-shaped hinge 612 and the top left and right
• the bottom section 642 of the opening 624 preferably contains the bottom T-shaped hinge 614 and
• the walls of the middle section 640 of the opening 624 may be spaced apart from the opposing edges of the mirror collection plate 610 by a distance ranging, for example, from about 30 to 150 microns. In a preferred embodiment, the walls of the middle section 640 of the opening 624 are
• the gap in the x-direction is different from the gap in the y-direction in order to optimally protect the mirror collection plate 610 from shocks.
• the gap between the mirror collection plate 610 and the middle section 640 of the opening 624 provides a spacing in the y-direction ranging from about 15 to 45 microns and a spacing in the x-direction ranging from about 50 to 180 microns in order to optimally limit shock loads on the mirror collection plate 610.
• the conductive layer 626 is preferably coupled to the outer periphery
• the conductive surface 626 preferably provides a conductive electrical path.
• the conductive layer 626 may be fabricated from any number of conventional commercially available materials such as, for example, gold, aluminum, or silver. In a preferred embodiment, the conductive layer 626 is fabricated from gold. In a preferred embodiment,
• the conductive layer 626 is bonded to the underlying substrate by an intermediate layer of titanium.
• the mirror 210 may be fabricated from any number of conventional commercially available materials such as, for example, silicon, plated metal or plastic.
• the mirror 210 is fabricated by micro- machining a silicon wafer using any one, or combination, of the known micro- machining processes.
• the released and free-standing mirror collection plate 610 is connected to the surrounding support frame, 600 by the T-shaped hinges, 612 and 614. In a preferred embodiment, the travel
• stop fingers, 616, 618, 620 and 622 provide overswing protection for the
• mirror collection plate 610 In a preferred embodiment, a 200-micron deep anisotropic deep reactive ion etching (DRIE) process is used to form very precise, narrow gaps for X-axis shock protection and Y-axis shock protection, where the mirror collection plate 610 is preferably completely confined within DRIE.
• DRIE deep anisotropic deep reactive ion etching
• the frame, 602, 604, 606 and 608, for X-axis and Y-axis translational or planar motion i.e. in the planes of the mirrored surface.
• DRIE refers to deep reactive ion etching of a substrate.
• the DRIE process is provided substantially as disclosed in United States Patent Nos. 5,498,312 and 5,501 ,893, which are incorporated herein by reference.
• the mirror collection plate 610 is supported and suspended by a pair of hinges 612 and
• hinges permit torsional movement or rotation of the mirror collection plate 610 about the common hinge axis 630 and movement of the
• the spacing 611 between the stops 616, 618, 620 and 621 and the frame 601 permit movement in the x-direction.
• the gap 647 provides a hinge compliance in the y-direction.
• the movements in the x and y directions are sometimes referred to the planar or translational movements and the hinges as springs.
• the beams 644 and 628 also permit the mirror collection plate 610 to move in the z-direction.
• the T-hinges provide the necessary compliance to the mirror collection plate motion in the y-direction, which improves the shock tolerance of the hinge to y-axis shock loads generated by the mirror collection plate 610.
• Prior art typically utilizes a straight-beam hinge, i.e. a beam connected to the frame without a T-member, such as the member 646. Such straight-beam hinges tend to buckle and fracture due to
• the mirror 210 preferably includes portions, 602, 604, 606 and 608, that are full-wafer thickness (e.g., 400 microns), and
• portions, 610 that are half-wafer thickness (e.g., 200 microns).
• the half-thickness mirror collection plate 610 reduces the amount of deep reactive ion etching (DRIE) and also improves the position accuracy of the mirror collection plate 610.
• the cavity 720 preferably etched in the
• center of the mirror collection plate 610 is preferably primarily used to improve the position accuracy of the mirror collection plate 610 and reduce the mass of the mirror collection plate 610 without substantially altering the resonant frequency.
• the backside of the mirror collection plate 610 preferably includes the Z travel-stops, 710 and 715, that preferably are full-wafer thickness (e.g.,
• the thicker travel-stops, 710 and 715 optimally maintain the mirror collection plate 610. Since the mirror collection plate 610, is preferably 200- microns thick, the thicker travel-stops, 710 and 715, optimally maintain the mirror collection plate 610. Since the mirror collection plate 610, is preferably 200- microns thick, the thicker travel-stops, 710 and 715, optimally maintain the mirror collection plate 610. Since the mirror collection plate 610, is preferably 200- microns thick, the thicker travel-stops, 710 and 715, optimally maintain the mirror collection plate 610. Since the mirror collection plate 610, is preferably 200- microns thick, the thicker travel-stops, 710 and 715, optimally maintain the mirror collection plate 610. Since the mirror collection plate 610, is preferably 200- microns thick, the thicker travel-stops, 710 and 715, optimally maintain the mirror collection plate 610. Since the mirror collection plate 610, is preferably 200- microns thick, the thicker
• collection plate 610 having minimum x-y plane dimensions of about 3-mm x 3-mm is preferred.
• right support members, 606 and 608, of the mirror 210 further include cutouts, 660A and 660B, positioned on opposite sides of the mirror collection
• the left and right support members, 606 and 608, is reduced. In this manner,
• the frequency response characteristics of the mirror 210 are enhanced.
• the bottom cap 215 includes a bottom
• the cap frame 1000 to provide support for the bottom cap.
• the frame 1000 includes support members and top and bottom travel stop members as described above for the top cap and shown in FIG. 3.
• the bottom cap further comprises an upper left beam 1035, an upper right beam 1040, a lower left beam 1045, a lower right beam 1050, a top conductive surface
• the thickness of the bottom cap frame 1000 may range, for example, from about 400 to 600 microns with preferred thickness ranging from about 400 to 450 microns to provide a compact structure having a low mass.
• the top travel stop member 1010 preferably limits the motion of the
• stop member 1010 is positioned within the plane of the top support member
• the thickness of the top travel stop member 1010 may range, for example, from about 350 to 550 microns. In a preferred embodiment, the thickness of the top travel stop 1010 ranges from about 350 to 380 microns in order to provide a compact structure having a low mass. In a particularly preferred embodiment, the top surface 1010A of the top travel stop member
• the length of the top travel stop member 1010 may range, for example, from about 1200 to 2800 microns. In a preferred embodiment, the length of the top travel stop member 1010 ranges from about 2000 to 2500 microns. In a particularly preferred embodiment, the length of the top travel stop member 1010 is selected to overlap with the
• mirror collection plate 610 of the mirror by about 300 microns.
• the bottom travel stop member 1020 preferably extends in a substantially orthogonal direction from the bottom support member 1015.
• the bottom travel stop member 1020 is otherwise substantially identical to
• the upper left beam 1035 preferably provides support and limits the
• the upper left beam 1035 preferably extends is a substantially orthogonal direction from the left support member 1025. In a preferred embodiment, the upper left beam 1035 is positioned within the plane of the left support member 1025.
• the thickness of the upper left beam 1035 may range, for example, from about 150 to 250 microns. In a preferred embodiment, the thickness of the upper left beam 1035 ranges from about 200 to 220 microns in order to optimally provide a compact structure having a low mass. In a particularly preferred embodiment, the top surface of the upper left beam 1035 is recessed below
• the top surface of the upper left beam 1035 is preferably positioned
• length of the upper left beam 1035 may range, for example, from about 1500 to 2200 microns. In a preferred embodiment, the length of the upper left beam 1035 is about 1800 microns.
• the upper right and lower left and right beams 1040, 1045 and 1050 are substantially identical to the upper left beam 1035. These beams are positioned within the plane of corresponding support members.
• the top conductive surface 1055 is preferably coupled to the outer
• the top conductive surface 1055 preferably provides a conductive electrical path.
• conductive surface 1055 further preferably provides a bonding ring for
• the top conductive surface 1055 may be fabricated from any number of conventional commercially available materials such as, for example, gold, aluminum, or silver. In a preferred embodiment, the top conductive surface 1055 is fabricated from gold. In a preferred embodiment, the top conductive
• the bottom conductive surface 1060 is preferably coupled to the
• the conductive surfaces 1055 and 1060 are conductive surfaces 1055 and 1060.
• the opening 1065 preferably permits the drive pad electrodes, 1310
• the opening 1065 preferably comprises a substantially rectangular opening of greater size than the mirror collection plate 610 of the mirror 210.
• member 220 includes a bottom plate 1305, a left drive pad electrode 1310, a right drive pad electrode 1315, a frame 1300, a conductive layer 1340, and
• the bottom plate 1305, and frame 1300 together provide structural
• the base member 220 preferably supports the bottom cap 215, mirror 210 and the top cap 205.
• the bottom plate 1305 preferably comprises a solid member fabricated from any number of conventional commercially available materials such as, for example, ceramic, silicon or glass. In a preferred embodiment, the thickness of the bottom plate 1305 ranges from about 200 to 400 microns.
• the left drive pad electrode 1310 is coupled to the bottom plate 1305.
• the left drive pad electrode 1310 preferably permits the mirror collection
• the mirror collection plate 610 of the mirror 210 oscillates about the axis 630.
• electrode 1310 includes a conductive layer 1310A that is coupled to the
• the conductive layer 1310A may be fabricated from any number of conventional commercially available materials such as, for example, metal, polysilicon or conductive epoxy. In a preferred embodiment, the conductive layer 1310A is fabricated from metal.
• the left drive pad electrode 1310 may have a top surface area ranging, for example, from about 3X10 6 to 10X10 6 microns. 2 In a preferred embodiment, the top surface area of the left drive pad electrode 1310 is about 4.5X10 6 microns 2 in order to optimally drive the mirror collection plate 610 of the mirror 210.
• the left drive pad electrode 1310 preferably extends from the bottom plate 1305 in a substantially orthogonal direction.
• drive pad electrode 1310 may extend from the bottom plate 1305 for a distance ranging, for example, from about 50 to 200 microns. In a preferred embodiment, the left drive pad electrode 1310 extends from the bottom plate
• gap between the top of the left drive pad electrode 1310 and the bottom of the mirror collection plate 610 of the mirror 210 ranges from about 300 to 400 microns.
• the right drive pad electrode 1315 is substantially identical to the left
• electrodes, 1310 and 1315 are positioned substantially equidistant from the
• the top support member 1320 is coupled to the bottom plate 1305,
• the top support member 1320 may have a length, width and height ranging, for example, from about 4000 to 6000 microns, 400 to 600 microns, and 400 to 600 microns. In a preferred embodiment, the top support member 1320 length, width and height are about 4900 microns, 375 microns, and 400 microns.
• the left support member 1330 is coupled to the bottom plate 1305, the top support member 1320, the bottom support member 1325 and the
• the left support member 1330 may have a length, width and height ranging, for example, from about 6000 to 9000 microns, 400 to 600 microns, and 400 to 600 microns. In a preferred embodiment, the left support member 1330 length, width and height are about 6800 microns, 375 microns, and 400 microns.
• the bottom support member 1325 is substantially identical to the top
• the conductive layer 1340 preferably extends around the periphery of
• the conductive layer 1340 preferably provides a conductive electric path for use in actuating the mirror collection plate 610 of the mirror 210.
• the conductive layer 220 may be fabricated from any number of conventional commercially available materials such as, for example, metal, polysilicon or conductive epoxy. In a preferred embodiment, the conductive layer 1340 is fabricated from gold.
• the conductive layer 1340 may be coupled to the conductive path 1345 using conventional methods.
• the base member 220 may be fabricated from any number of conventional commercially available materials such as, for example, ceramic, silicon or glass using any number of conventional fabrication processes.
• the base 220 preferably provides electrode access to the mirror collection plate 610 for electrostatic actuation and capacitive position sensing
• bottom cap 215, preferably provides electrical contact between the base
• the wafer bonding process preferably allows the bottom cap 215 to be in direct
• mirror collection plate 610 preferably can be electrically accessed, controlled,
• FIG. 16 a sub-assembly including the top cap 205 and the mirror 210 is illustrated. As illustrated in FIG. 16, the travel stops,
• the top cap 205 protects the mirror collection plate 610 from z-axis shock while also minimizing the shadowing/overlapping of the reflective surface 628 of the mirror collection plate 610. Furthermore, the
• the travel stop fingers, 1010 and 1020 protect the mirror collection plate 610 from z-axis shock while also maximizing the drive area of the drive pad electrodes, 1310 and 1315.
• top cap 205 and bottom cap 215 all of the interior walls of the top cap 205 and bottom cap 215 include
• the mirror collection plate 610 may be rotated out of plane by about 14° in both directions. In a preferred embodiment,
• the mirror 210 is about 60 ⁇ 10 microns for rotation ranging from -14° to
• the clearance between the mirror collection plate 610 and the travel stops, 320 and 1020 is about 20-60 microns.
• the travel stop fingers' 310 and 320 dimensions are chosen to make them sufficiently compliant in the z-direction to dissipate the Z-axis shock impact energy of the mirror hitting (urging) the travel-stop fingers. This compliancy provides a shock energy dissipation factor (not comprehended in the prior art) makes the resulting mirror assembly more robust to shock loads.
• the travel-stop fingers 616, 618, 620, and 626 are similarly made to have sufficient compliance in the x-direction to dissipate X-axis shock impact of the mirror plate hitting frame 600.
• top cap 205 protect the mirror 210 from Z-axis shock while minimizing the shadowing/overlap of the mirror collection plate 610, thus providing the external laser optical access to the micromirror.
• top cap 205 which preferably sets the gap between the mirror collection
• the tapered walls around the inside perimeter of the top cap 205 are preferably for capturing the mirror collection plate 610
• the bottom cap 215 preferably protect the mirror collection plate 610 from Z-axis shock while maximizing the area of the drive pad electrodes, 1310 and 1315.
• the caps, 205 and 215, preferably constrain the mirror collection plate 610 from Z-axis translational motion, while promoting torsional rotation of the mirror collection plate 610 about the axis 630.
• the bottom cap 215 also preferably includes the beams, 1025, 1040, 1045, and 1050, for facilitating the handling of defective mirrors during the fabrication process.
• hinges 612 and 614 decouples the rotational spring constants from the translational spring constants. In this manner, the mirror collection plate 610 is optimally protected from vibration and shock loads.
• the beam A is directed to the mirror collection plate 610 at an angle of 45 ° and results in the reflected beam B.
• the reflected laser beams are bound by the rays B' and B .
• the tapered walls and rim cut-outs, 330 and 340, of the top cap 205 minimize clipping of the incident and reflected laser beams.
• the tapered walls of the top cap 205 minimize clipping of the incident and
• a mirror assembly has been described that includes a mirror, a top cap and a bottom cap.
• the mirror includes a mirror support structure, a pair of T-shaped hinges coupled to the mirror support structure and a mirrored plate coupled to the T-shaped hinges.
• the mirrored plate includes one or more travel stops for limiting movement of the mirrored plate.
• the top cap is coupled to one side of the mirror.
• the top cap includes a top cap support structure including an opening for permitting light to reflect off of the mirrored plate and one or more travel stops coupled to the top cap support structure for limiting movement of the mirrored plate.
• the bottom cap is coupled to another side of the mirror.
• the bottom cap includes a bottom cap support structure including an opening and one or more travel stops coupled to the bottom cap support structure for limiting movement of the mirrored plate.
• the mirror support structure includes a top support member, a bottom support member, a right side support member and a left side support member.
• the mirror support structure includes an opening.
• the support structure opening includes a pair of oppositely positioned cut-outs.
• the support structure opening is complementary shaped with respect to the mirrored plate.
• the spacing between the edges of the support structure opening and the mirrored plate ranges from about 15 to 180 microns.
• the pair of T-shaped hinges include a top T-shaped hinge and a bottom T-shaped hinge positioned in opposing relation to the top T-shaped hinge.
• the mirrored plate includes a plate member including a first side and a second side, a reflective surface coupled to the first side of the plate member, a cavity formed in the second side of the plate member and a pair of travel stops coupled to the second side of the plate member.
• the plate member cavity includes a V-shaped cross section.
• the mirrored plate includes a plate member and one or more travel stops extending from the plate member.
• the travel stops are positioned in the plane of the plate member.
• the plate member travel stops that are positioned in the plane of the plate member have a length and thickness ranging from about 500 to 2000 microns and
• the plate member extend from the plane of the plate member.
• the plate member travel stops that extend from the plane of the plate member have a length ranging from about 200 to 250 microns.
• the mirrored plate includes a plate member and a plurality of travel stops extending from the plate member.
• at least one of the plate member travel stops in positioned in the plane of the plate member and at least one of the travel stops extends from the plane of the plate member.
• each T-shaped hinge includes a first member and a second member coupled to the first member.
• the first and second members are substantially orthogonal.
• the length, width and thickness of the first hinge member ranges from about 500 to 4500 microns, 10 to 100 microns and 10 to 100 microns.
• the length, width and thickness of the second hinge member ranges from about 400 to 1800 microns, 2 to 35 micron and 2 to 35 microns.
• each T-shaped hinge provides a torsional spring.
• the spring constant ranges from about 2x10 "9 to 10x10 "7 Ibf-ft/radian.
• the top cap travel stops are positioned in the plane of the top cap support structure. In a preferred embodiment, the thickness of the top cap travel stops are less than the thickness of the top cap support structure.
• the opening in the top cap support structure includes a pair of oppositely positioned cut-outs.
• the cut-outs include tapered walls.
• the taper angle of the tapered walls ranges from about 55 to 60 degrees.
• the top cap opening includes tapered walls.
• the taper angle of the tapered walls ranges from about 55 to 60 degrees.
• the bottom cap travel stops are positioned in the plane of the bottom cap support structure. In a preferred embodiment, the thickness of the bottom cap travel stops are less than the thickness of the bottom cap support structure.
• the bottom cap opening includes tapered walls.
• the taper angle of the tapered walls ranges from about 55 to 60 degrees.
• the mirror assembly further includes a base member coupled to the bottom cap.
• the base member includes one or more drive pads for actuating the mirrored plate.
• the base member includes one or more sensing members for sensing the position of the mirrored plate.
• the bottom cap further includes one or more support members for supporting the mirrored plate during the manufacturing process.
• the length and thickness of the top cap travel stops range from about 800 to 2800 microns and 340 to 580 microns.
• the length and thickness of the bottom cap travel stops range from about 800 to 2800 microns and 340 to 580 microns.
• one or more of the T-shaped hinges include a first member and a second member coupled to the first member, wherein the second member is perpendicular to the first member.
• one or more of the T-shaped hinges include a first member and a second member coupled to the first member, wherein the second member is serpentine.
• one or more of the T-shaped hinges include a first member and a second member coupled to the first member, wherein the second member is offset from the center of the first member.
• one or more of the T-shaped hinges include a first member and a second member coupled to the first member, wherein the second member intersects the first member at an acute angle.
• each T-shaped hinge includes a translational spring constant and a rotational spring constant that are decoupled from one another.
• a mirror assembly has also been described that includes a support structure, a pair of T-shaped hinges coupled to the support structure and a mirrored plate coupled to the T-shaped hinges.
• the mirrored plate includes one or more travel stops for limiting movement of the mirrored plate.
• each T-shaped hinge includes a rotational spring constant and a translational spring constant that are decoupled.
• the support structure includes a top support member, a bottom support member, a right side support member and a left side support member.
• the support structure includes an opening.
• the opening includes a pair of oppositely positioned cut-outs.
• the opening is complementary shaped with respect to the mirrored plate.
• the spacing between the edges of the opening and the mirrored plate ranges from about 15 to 180 microns.
• the pair of T-shaped hinges include a top T-shaped hinge and a bottom T-shaped hinge positioned in opposing relation to the top T-shaped hinge.
• the mirrored plate includes a plate member including a first side and a second side, a reflective surface coupled to the first side of the plate member, a cavity formed in the second side of the plate member and a pair of travel stops coupled to the second side of the plate member.
• the cavity includes a V-shaped cross section.
• the mirrored plate includes a plate member and one or more travel stops extending from the plate member.
• the travel stops are positioned in the plane of the plate member. In a preferred embodiment, the travel stops that are positioned in the plane of the plate member have a length and thickness that range from about 500 to 2000 microns and 200 to 600 microns. In a preferred embodiment, the travel stops extend from the plane of the plate member. In a preferred embodiment, the travel stops that extend from the plane of the plate member have a length that extends from about 200 to 250 microns. In a preferred embodiment, the mirrored plate includes a plate member and a plurality of travel stops extending from the plate member. In a preferred embodiment, at least one of the travel stops in positioned in the plane of the plate member and at least one of the travel stops extends from the plane of the plate member.
• each T-shaped hinge includes a first member and a second member coupled to the first member.
• the first and second members are substantially orthogonal.
• the length, width and thickness of the first member ranges from about 500 to 4500 microns, 10 to 100 microns and 10 to 100 microns.
• the length, width and thickness of the second member ranges from about 400 to 1800 microns, 20 to 35 microns and 2 to 35 microns.
• each T-shaped hinge provides a torsional spring.
• the spring constant ranges from about 2x10 "9 to 10x10 "7 Ibf- ft/radian.
• one or more of the T-shaped hinges include a first member and a second member coupled to the first member, wherein the second member is perpendicular to the first member. In a preferred embodiment, one or more of the T-shaped hinges include a first member and a second member coupled to the first member, wherein the second member is serpentine. In a preferred embodiment, one or more of the T-shaped hinges include a first member and a second member coupled to the first member, wherein the second member is offset from the center of the first member. In a preferred embodiment, one or more of the T-shaped hinges include a first member and a second member coupled to the first member, wherein the second member intersects the first member at an acute angle.
• An apparatus has also been described that includes one or more T- shaped springs and a mass coupled to the T-shaped springs.
• the mass includes a reflective surface.
• the mass includes one or more travel stops for limiting movement of the mass.
• the apparatus further includes a top cap coupled to the top of the mass, wherein the top cap includes one or more travel stops for limiting movement of the mass.
• the apparatus further includes a bottom cap coupled to bottom of the mass, wherein the bottom cap includes one or more travel stops for limiting movement of the mass.
• the apparatus further includes a top cap coupled to the top of the mass and a bottom cap coupled to the bottom of the mass, wherein the top and bottom caps each include one or more travel stops for limiting movement of the mass.
• each T-shaped hinge includes a rotational spring constant and a translational spring constant that are decoupled.
• the apparatus comprises an accelerometer.
• the apparatus comprises a gyroscope.
• An apparatus also has been described that includes a housing, a mass, and one or more springs for coupling the mass to the housing.
• Each spring includes a rotational spring constant and a translational spring constant. The rotational spring constant is decoupled from the translational spring constant.
• the springs are fabricated by a process including micromachining a substrate.
• the housing, mass and springs are fabricated by a process including micromachining a substrate.
• each spring comprises a plurality of springs.
• each spring is T-shaped.
• the apparatus further includes a top cap coupled to the top of the housing including a top cap cutout and a bottom cap coupled to the bottom of the housing including a bottom cap cutout.
• each cutout includes tapered side walls.
• the tapered side walls are rotated from the vertical direction at an angle ranging from about 15 to 45 degrees.
• a method of resiliently supporting a mass in a housing also has been described that includes coupling the mass to the housing using one or more springs having translational spring constants and rotational spring constants and decoupling the translational spring constants from the rotational spring constants.
• the springs are fabricated by a process including micromachining a substrate.
• the housing, mass and springs are fabricated by a process including micromachining a substrate.
• each spring comprises a plurality of springs.
• each spring is T-shaped.
• method further includes limiting movement of the mass when it is rotated from a rest position.
• limiting movement of the mass when it is rotated from a rest position includes limiting translation of the mass when it is rotated from the rest position.
• a method of resiliently supporting a mass in a housing also has been described that includes limiting translational movement of the mass in the X, Y and Z directions and limiting rotational movement of the mass.
• the housing and mass are fabricated by a process including micromachining a substrate.
• the method further includes limiting movement of the mass when it is rotated from a rest position.
• limiting movement of the mass when it is rotated from a rest position includes limiting translation of the mass when it is rotated from the rest position.
• An apparatus also has been described that includes a housing and a mass resiliently coupled to the housing, the mass including one or more travel stops for limiting rotational and translational movement of the mass.
• the housing includes an opening for receiving the mass that limits the translational movement of the mass.
• the apparatus further includes a top cap coupled to the top of the housing and a bottom cap coupled to the bottom of the housing.
• the top and bottom caps limit movement of the mass when it is rotated out of its rest position within the housing.
• the top and bottom caps includes cutouts.
• each cutout includes tapered side walls.
• the tapered side walls are rotated from the vertical direction at an angle ranging from about 15 to 45 degrees.
• each cutout includes tapered side walls.
• the tapered side walls are rotated from the vertical direction at an angle ranging from about 15 to 45 degrees.
• the housing and reflective surface are fabricated by a process including micromachining a substrate.
• a method of reflecting rays of light also has been described that includes providing a reflective surface and providing an optical pathway for accessing the reflective surface including one or more cutouts for minimizing clipping of the incident and reflected light rays.
• the optical pathway includes sidewalls that are rotated from the vertical direction at an angle ranging from about 15 to 45 degrees.
• the optical pathway and reflective surface are fabricated by a process including micromachining a substrate.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Micromachines (AREA)
• Optical Elements Other Than Lenses (AREA)
• Mechanical Optical Scanning Systems (AREA)
• Rear-View Mirror Devices That Are Mounted On The Exterior Of The Vehicle (AREA)
• Sliding-Contact Bearings (AREA)
• Mounting And Adjusting Of Optical Elements (AREA)
• Mechanical Light Control Or Optical Switches (AREA)
• Investigating Or Analysing Biological Materials (AREA)

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• 1999
  • 1999-07-13 US US09/352,835 patent/US6315423B1/en not_active Expired - Lifetime
• 2000
  • 2000-07-13 CA CA2378736A patent/CA2378736C/en not_active Expired - Lifetime
  • 2000-07-13 JP JP2001510032A patent/JP2003527621A/ja active Pending
  • 2000-07-13 EP EP00947273A patent/EP1200865B1/en not_active Expired - Lifetime
  • 2000-07-13 AT AT00947273T patent/ATE400831T1/de not_active IP Right Cessation
  • 2000-07-13 AU AU60911/00A patent/AU6091100A/en not_active Abandoned
  • 2000-07-13 WO PCT/US2000/018998 patent/WO2001004680A1/en not_active Ceased
  • 2000-07-13 DE DE60039432T patent/DE60039432D1/de not_active Expired - Lifetime
• 2001
  • 2001-06-01 US US09/873,054 patent/US6454421B2/en not_active Expired - Lifetime
• 2002
  • 2002-01-11 NO NO20020140A patent/NO326146B1/no not_active IP Right Cessation

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