# US 2010/0169903 A1 · Drive system for driving a movable part and disk drive unit comprising such drive system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0169903 A1 - Document ID: US20100169903A1 - Status: Published application - Kind: A1 - Application number: 12/063,238 - Filed: 2006-07-28 - Published: 2010-07-01 - Earliest claimed: 2005-08-08 - Assignees: Koninklijke Philips Electronics N.V. - Inventors: Waltherus Cornelis Jozef Bierhoff - Web page: https://patentgrep.com/patent/US20100169903A1 ## CPC - G11B 7/08511: {with focus pull-in only} - G11B 7/1376: Collimator lenses {(collimators per se G02B27/30)} - G11B 2007/0013: {for carriers having multiple discrete layers} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract The invention provides a drive system for driving a lens holder (6) of the optical system in a disk drive unit. It comprises a movable part (8) connected to the lens holder, and a base (7) including a guide (9) for guiding the movable part. A drive motor comprises a stator (12) fixed with respect to the base and a translator (13) movable with respect to the stator upon actuation of the motor. A return mechanism (21) is connected between the translator and the movable part for bringing the rotor/translator in a starting position with respect to the movable part in a rest condition of the drive motor. A portion (18) of the movable part is in the path of movement of the translator, while there is a free stroke (20) between the portion of the movable part and the translator in the starting position of the translator. As a result, the translator will hit the movable part, thereby overcoming the static friction between the movable part and the base. ## Claims ### Claim 1 A drive system for driving a movable part (8), comprising a base (7) including a guide (9) for guiding the movable part, a drive motor comprising a stator (12) fixed with respect to the base and a rotor/translator (13) movable with respect to the stator upon actuation, and a return mechanism (21) connected between the rotor/translator and the movable part for bringing the rotor/translator in a starting position with respect to the movable part in a rest condition of the drive motor, wherein a portion (18) of the movable part (8) is in the path of movement of the rotor/translator (13), and wherein there is a free stroke (20) between said portion of the movable part and the rotor/translator in the starting position of the rotor/ translator. ### Claim 2 (depends on 1) The drive system of claim 1, wherein the rotor/translator (13) is adapted to move in opposite directions, and the free stroke (20) of the rotor/translator is present in two opposite directions. ### Claim 3 (depends on 1) The drive system of claim 1, wherein the stator (12) co-operates with a translator (13) adapted to make a linear movement. ### Claim 4 (depends on 1) The drive system of claim 1, wherein the return mechanism (21, 22) includes at least one spring member (21). ### Claim 5 (depends on 4) The drive system of claim 4, wherein the translator (13) is an elongated member and one spring member (21) is connected between one end of the translator (13) and an adjacent portion of the base (7). ### Claim 6 (depends on 5) The drive system of claim 5, wherein the spring member (21) is a substantially flat spring positioned substantially transverse to the direction of movement of the drivable part (8). ### Claim 7 (depends on 1) The drive system of claim 1, wherein the stator (12) includes at least one coil (14) and the rotor/translator (13) comprises a magnet. ### Claim 8 (depends on 7) The drive system of claim 7, wherein the movable part (8) is guided on the base (7) by means of a linear guide (9), whereas the base includes at least one magnetizable member (16) positioned such that the interaction between the translator magnet (13) and the magnetizable member (16) keeps the movable part and the base in sliding engagement. ### Claim 9 (depends on 8) The drive system of claim 8, wherein the translator magnet (13) is positioned between the linear guide (9) and the magnetizable members (16). ### Claim 10 (depends on 1) The drive system of claim 1, wherein at least one mass is attached to the magnet. ### Claim 11 (depends on 5) The drive system of claim 5, wherein the drive control is adapted to energize the coils of the drive with a frequency matching the natural frequency of the drive system. ### Claim 12 (depends on 1) Disk drive unit comprising the drive system as claimed in claim 1 and comprising an optical system including an optical pickup unit and a rotatable turntable for supporting an optical disk.