# US 12,222,580 B2 · Lens autofocus actuating device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,222,580 B2 - Document ID: US12222580B2 - Status: Granted - Kind: B2 - Application number: 17/713,685 - Filed: 2022-04-05 - Published: 2022-07-21 - Granted: 2025-02-11 - Earliest claimed: 2019-04-26 - Assignees: TDK Taiwan Corp. - Applicants: TDK Taiwan Corp. - Inventors: Chi-Wei Chiu - Web page: https://patentgrep.com/patent/US12222580B2 ## CPC - G02B 7/08: adapted to co-operate with a remote control mechanism - F03G 7/06143: {Wires} - F03G 7/0665: {controlled displacement, e.g. by using a lens positioning actuator} - G02B 7/026: {using retaining rings or springs (G02B7/027 takes precedence)} - G02B 7/09: adapted for automatic focusing or varying magnification - G03B 13/36: Autofocus systems - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - F03G: SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR (arrangements in connection with power supply in vehicles from force of nature B60K16/00; electric propulsion with power supply in vehicles from force of nature B60L8/00) - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) ## Abstract A lens autofocus actuating device includes a base, a guide rail unit, a lens carrier, an actuating member, a plurality of balls, and a shell. The base includes an upper surface. The guide rail unit is disposed on the upper surface of the base. The lens carrier is disposed above the base. The lens carrier is located between a plurality of position-limiting members. The actuating member is disposed on the upper surface of the base. The actuating member comprises two electrode terminal pairs and two shape-memory alloy wires. The balls are divided into groups. The shell is connected to the base. ## Claims ### Claim 1 A lens autofocus actuating device, comprising: a base comprising an upper surface; a guide rail unit disposed on the upper surface of the base; a lens carrier, disposed above the base, the lens carrier comprises a protrusion; an actuating member, disposed on the upper surface of the base, comprising two electrode terminal pairs and two shape-memory alloy wires, wherein the two electrode terminal pairs each has two electrodes, one of the electrodes in each of the two electrode terminal pairs is electrically connected to each other, the two shape-memory alloy wires are disposed opposite each other, wherein each shape-memory alloy wire is in contact with the protrusion of the lens carrier, and two ends of each shape-memory alloy wire are connected to the electrodes of each group of the electrode terminal pairs, wherein the shape-memory alloy wires are driven by an electric current to produce thermal deformation and then actuate the lens carrier to move relative to the base; a plurality of balls divided into groups; and a shell connected to the base to cover at least the guide rail unit, the lens carrier, and the actuating member; wherein the guide rail unit comprises: a fixing ring; and a plurality of position-limiting members disposed vertically on the fixing ring. ### Claim 2 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein a material of the fixing ring and the position-limiting members is metal, plastic steel or plastic. ### Claim 3 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein the fixing ring of the guide rail unit is held in contact with the position-limiting members by a welding joint, by being glued with an adhesive, by high-temperature welding, or by laser welding. ### Claim 4 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein the base comprises a central through hole in a center, wherein the shell, the fixing ring and the lens carrier respectively comprises through holes corresponding to the central through hole of the base. ### Claim 5 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein the lens carrier is located between the plurality of position-limiting members, and an outer side surface of the lens carrier comprises a plurality of cavities, each of the cavities and the corresponding position-limiting member form a disposing space, each group of the balls is positioned in the corresponding disposing space and in contact with surfaces of the position-limiting members and the cavities. ### Claim 6 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein each position-limiting member is L-shaped, wherein the L-shape has a notch, and the notch of the L-shape faces an outer side surface of the lens carrier. ### Claim 7 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein the lens carrier is disposed on the base, and the lens carrier is located within a circular range formed by the position-limiting members. ### Claim 8 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein the position-limiting members are uniformly disposed on the fixing ring. ### Claim 9 (depends on 8) The lens autofocus actuating device as claimed in claim 8, wherein an included angle between each of the position-limiting members is 120 degrees. ### Claim 10 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein the base further comprises a plurality of positioning members, wherein each positioning member is disposed to correspond with the respective position-limiting member on the upper surface of the base, to position the position-limiting members. ### Claim 11 (depends on 10) The lens autofocus actuating device as claimed in claim 10, wherein each group of positioning members comprises two adjacent protrusions, and each position-limiting member has a L-shaped structure, wherein the L-shaped structures of the position-limiting members are pressed against the protrusions of the positioning members, so as to fix a position of the position-limiting members. ### Claim 12 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein four electrodes are disposed at four corners of the base, and the two shape-memory alloy wires are disposed opposite each other on two sides of the base. ### Claim 13 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein the shape-memory alloy wires are approximately V-shaped in an initial state. ### Claim 14 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein a material of the balls is metal or precision ground ceramics. ### Claim 15 (depends on 1) The lens autofocus actuating device as claimed in claim 1, further comprising: a circuit board, located at one side of the lens carrier, disposed vertically on the upper surface of the base, with a Hall sensing member electrically connected to the circuit board; and a magnetic member, disposed facing the Hall sensing member in a cavity on outer side of the lens carrier. ### Claim 16 (depends on 1) The lens autofocus actuating device as claimed in claim 1, further comprising two resilient members disposed opposite each other between an upper surface of the lens carrier and the shell, and the resilient members provide a returning force to move the lens carrier in s direction of the base after the shape-memory alloy wires cool down. ### Claim 17 (depends on 16) The lens autofocus actuating device as claimed in claim 16, wherein there is an even number of resilient members. ### Claim 18 (depends on 1) The lens autofocus actuating device as claimed in claim 1, wherein the upper surface of the base comprises a support plate disposed vertically on one side of the base. ### Claim 19 (depends on 18) The lens autofocus actuating device as claimed in claim 18, further comprising a circuit board affixed to the support plate.