# US 7,412,157 B2 · Lens driving device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,412,157 B2 - Document ID: US7412157B2 - Status: Granted - Kind: B2 - Application number: 11/234,331 - Filed: 2005-09-23 - Published: 2006-03-30 - Granted: 2008-08-12 - Earliest claimed: 2004-09-24 - Assignees: LG Electronics Inc. - Inventors: Jae-Hyoung Park; Chang-Hyeon Ji; Man-Hyo Ha; Seoung-Hyok Kim; Jong-Uk Bu; Young-Joo Yee - Web page: https://patentgrep.com/patent/US7412157B2 ## CPC - H02N 2/0065: {Friction interface (friction linings F16D69/00)} - G03B 17/00: Details of cameras or camera bodies; Accessories therefor (lens hoods or caps G03B11/04) - H02N 2/08: using travelling waves {, i.e. Rayleigh surface waves} - H02N: ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR - 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 driving device includes a substrate which generates surface acoustic waves on its surface and a movable unit which is coupled to an optical lens and executes translation above the substrate using the surface acoustic waves. The lens driving device can implement translation of the lens without a separate mechanism, unlike the conventional driving devices using motors and screws, thereby satisfying the recent trend towards miniaturization and lightness to be used in a variety of industrial fields that use optical lenses. ## Claims ### Claim 1 A lens driving device, comprising: a substrate to generate surface acoustic waves on a surface of the substrate; and a movable unit coupled to an optical lens and executing translation on the substrate using the surface acoustic waves, wherein a plurality of protrusions which have a passage to ensure smooth air flow between the movable unit and the substrate and prevent damping due to air, are provided on a surface of the movable unit which contacts the substrate. ### Claim 2 (depends on 1) The lens driving device as set forth in claim 1, further comprising: a pair of interdigitating electrodes provided on respective opposite ends of the substrate. ### Claim 3 (depends on 1) The lens driving device as set forth in claim 1, further comprising: a pressure unit to apply pressure to both the movable unit and the substrate. ### Claim 4 (depends on 3) The lens driving device as set forth in claim 3, wherein the pressure unit comprises one selected from a combination of permanent magnets, a combination of a permanent magnet and a metal, and a combination of mechanical springs. ### Claim 5 (depends on 4) The lens driving device as set forth in claim 4, wherein the pressure unit comprises one selected from a combination of a permanent magnet and a metal and a combination of mechanical springs. ### Claim 6 (depends on 1) The lens driving device as set forth in claim 1, wherein the substrate is made of one of lithium niobate (LiNbO3), lithium tantalite (LiTaO3), and PZT material. ### Claim 7 (depends on 6) The lens driving device as set forth in claim 6, wherein the substrate is made of one of lithium tantalite (LiTaO3) and PZT material. ### Claim 8 (depends on 1) The lens driving device as set forth in claim 1, wherein the movable unit moves in an opposite direction to a propagation direction of the surface acoustic waves. ### Claim 9 (depends on 1) The lens driving device as set forth in claim 1, wherein the protrusions are arranged in an array. ### Claim 10 (depends on 1) The lens driving device as set forth in claim 1, wherein each protrusion has one shape selected from a circular shape, a rhombic shape, a rectangular shape and a sine wave shape. ### Claim 11 (depends on 1) The lens driving device as set forth in claim 1, wherein the passage is defined in a same direction as a driving direction of the movable unit. ### Claim 12 (depends on 1) The lens driving device as set forth in claim 1, wherein the optical lens comprises at least one lens conducting a zoom function. ### Claim 13 (depends on 1) The lens driving device as set forth in claim 1, wherein the optical lens comprises at least one lens conducting an auto focus function. ### Claim 14 (depends on 1) The lens driving device as set forth in claim 1, wherein the optical lens is coupled to the movable unit by a connection unit. ### Claim 15 (depends on 14) The lens driving device as set forth in claim 14, wherein the connection unit comprises a spring. ### Claim 16 (depends on 1) The lens driving device as set forth in claim 1, wherein the optical lens comprises at least one zoom lens and at least one auto focus lens, and at least one first movable unit, coupled to the zoom lens, and at least one second movable unit, coupled to the auto focus lens, are integrated on the same substrate. ### Claim 17 (depends on 1) The lens driving device as set forth in claim 1, wherein the movable unit comprises one of silicon, ceramic, metal, and polymer. ### Claim 18 (depends on 1) The lens driving device as set forth in claim 1, further comprising: an upper pressure unit provided on the movable unit; and a lower pressure unit provided under the substrate, wherein the substrate and the movable unit are in close contact with each other at a predetermined pressure due to the upper and lower pressure units. ### Claim 19 (depends on 18) The lens driving device as set forth in claim 18, wherein an area of a surface of the upper pressure unit contacting the movable unit is same as an area of a surface of the movable unit contacting the upper pressure unit. ### Claim 20 (depends on 19) The lens driving device as set forth in claim 19, wherein an area of a surface of the lower pressure unit contacting the substrate is same as an area of a surface of the substrate contacting the lower pressure unit.