# US 2021/0242807 A1 · Linear comb driver with non-uniform fingers for alignment stability at discrete positions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0242807 A1 - Document ID: US20210242807A1 - Status: Published application - Kind: A1 - Application number: 16/913,907 - Filed: 2020-06-26 - Published: 2021-08-05 - Earliest claimed: 2020-01-30 - Assignees: Lumentum Operations LLC - Applicants: Lumentum Operations LLC - Inventors: Wenlin Jin; Gonzalo WILLS - Web page: https://patentgrep.com/patent/US20210242807A1 ## CPC - G02B 26/0841: {the reflecting element being moved or deformed by electrostatic means} - H02N 1/008: {Laterally driven motors, e.g. of the comb-drive type} - B81B 3/00: Devices comprising flexible or deformable elements, e.g. comprising elastic tongues or membranes (B81B5/00 takes precedence) - B81B 3/0021: {Transducers for transforming electrical into mechanical energy or vice versa (dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00)} - G02B 7/182: for mirrors - B81B 2201/033: Comb drives - B81B 2203/04: Electrodes - B81B 2203/051: Translation according to an axis parallel to the substrate - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H02N: ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR - B81B: MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES (piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/00, H10N35/00) ## Abstract A linear comb drive may include a stator. The linear comb drive may include a rotor. At least one of the stator or the rotor may include a comb with one or more horizontally-extending fingers that have a tooth-shape formed by one or more prongs that extend vertically from the one or more fingers in a plane formed by the one or more fingers. ## Claims ### Claim 1 A linear comb driver, comprising: a stator; and a rotor, wherein at least one of the stator or the rotor includes a comb with one or more horizontally-extending fingers that have a tooth-shape formed by one or more prongs that extend vertically from the one or more fingers in a plane formed by the one or more fingers. ### Claim 2 (depends on 1) The linear comb driver of claim 1, further comprising: a movable element attached to the rotor. ### Claim 3 (depends on 2) The linear comb driver of claim 2, wherein the tooth-shape is configured to provide, for the linear comb driver, a higher stability number for the movable element at a first one or more positions than at a second one or more positions. ### Claim 4 (depends on 3) The linear comb driver of claim 3, wherein the first one or more positions are defined by an alignment of the one or more prongs to another one or more prongs of the stator or the rotor and the second one or more positions are defined by a lack of alignment of the one or more prongs to the other one or more prongs. ### Claim 5 (depends on 1) The linear comb driver of claim 1, wherein the one or more prongs include a first set of prongs attached to the stator, and wherein the one or more prongs include a second set of prongs attached to the rotor. ### Claim 6 A comb driver finger assembly, comprising: a base element; a finger element attached to the base element and extending in a first direction; and at least one prong element attached to the finger element and extending in a plane of the finger element and in a second direction perpendicular to the first direction. ### Claim 7 (depends on 6) The comb driver finger assembly of claim 6, wherein the at least one prong element is a single prong. ### Claim 8 (depends on 6) The comb driver finger assembly of claim 6, wherein the at least one prong element is a plurality of prongs disposed at different distances along the finger element in the first direction and separated by a threshold distance in the first direction. ### Claim 9 (depends on 6) The comb driver finger assembly of claim 6, wherein the at least one prong element is associated with a rectangular shape. ### Claim 10 (depends on 6) The comb driver finger assembly of claim 6, wherein the at least one prong element is associated with a non-rectangular shape. ### Claim 11 (depends on 6) The comb driver finger assembly of claim 6, wherein the at least one prong element is a plurality of prong elements, and wherein a first prong element, of the plurality of prong elements, is associated with a first shape and a second prong element, of the plurality of prong elements, is associated with a second shape. ### Claim 12 (depends on 6) The comb driver finger assembly of claim 6, wherein the at least one prong element is a plurality of prong elements, and wherein a first prong element, of the plurality of prong elements, is associated with a first height in the second direction and a second prong element, of the plurality of prong elements, is associated with a second height in the second direction. ### Claim 13 A micro-electro-mechanical device, comprising: a stator comb including a first one or more fingers, wherein at least one of the first one or more fingers is associated with a first tooth-shape formed by a first one or more prongs, wherein the first one or more prongs extend from the first one or more fingers in a first plane formed by the first one or more fingers, a rotor comb including a second one or more fingers, wherein at least one of the second one or more fingers is associated with a second tooth-shape formed by a second one or more prongs, wherein the second one or more prongs extend from the second one or more fingers in a second plane formed by the second one or more fingers, and wherein the first one or more fingers are configured to interleave with the second one or more fingers; and a movable element mounted to the rotor comb. ### Claim 14 (depends on 13) The micro-electro-mechanical device of claim 13, wherein the first tooth-shape includes a first one or more peaks formed by the first one or more prongs and a first one or more valleys adjacent to the first one or more peaks formed by the first one or more prongs; and wherein the second tooth-shape includes a second one or more peaks formed by the second one or more prongs and a second one or more valleys adjacent to the second one or more peaks formed by the second one or more prongs. ### Claim 15 (depends on 13) The micro-electro-mechanical device of claim 13, wherein the first tooth-shape and the second tooth-shape are configured to provide, for the micro-electro-mechanical device, a higher stability number for the movable element at a first one or more positions than at a second one or more positions, wherein the first one or more positions are defined by an alignment of the first one or more prongs to the second one or more prongs, and the second one or more positions are defined by a lack of alignment of the first one or more prongs to the second one or more prongs. ### Claim 16 (depends on 15) The micro-electro-mechanical device of claim 15, wherein a capacitance derivative of the first one or more prongs and the second one or more prongs is a first value at a particular position of the first one or more positions and the capacitance derivative of the first one or more prongs and the second one or more prongs is a second value at a particular position of the second one or more positions, and wherein the first value is greater than the second value. ### Claim 17 (depends on 15) The micro-electro-mechanical device of claim 15, wherein a voltage derivative of the first one or more prongs and the second one or more prongs is a first value at a particular position of the first one or more positions, and the voltage derivative of the first one or more prongs and the second one or more prongs is a second value at a particular position of the second one or more positions, and wherein the first value is greater than the second value. ### Claim 18 (depends on 15) The micro-electro-mechanical device of claim 15, further comprising: a set of optical ports alignable to the movable element, and wherein a pitch between positions of the first one or more positions corresponds to a pitch between ports of the set of optical ports. ### Claim 19 (depends on 15) The micro-electro-mechanical device of claim 15, wherein the first one or more prongs include a first quantity of prongs and the second one or more prongs include a second quantity of prongs, and wherein the first quantity and the second quantity are a common quantity. ### Claim 20 (depends on 13) The micro-electro-mechanical device of claim 13, wherein the movable element is at least one of: a mirror, a waveguide, a prism, a grating, an optical transmitter, an optical receiver, another micro-electro-mechanical device, or an optical micro-electro-mechanical device.