Abstract: An optical scanning device for scanning tracks of an optical record carrier (OD) using a radiation beam, the device including an optical head (16), defining an optical axis (OA), for converging the radiation beam to a spot when scanning the record carrier; and a rotary arm (2) for moving the optical head across the record carrier. The device further comprises a rotatably mounted diffraction grating (8) for generating satellite beams for performing multi-spot tracking. Rotation of the grating is arranged to move the satellite beams, relative to the optical axis of the optical head, in correspondence with rotation of the rotary arm.

Abstract: An optical scanning device for scanning an information layer of an optical record carrier and including a rotary aim (2; 102; 202; 302; 402; 502) which is arranged to swing about a rotation axis (CR) to alter an angular position of the rotary arm about the rotation axis; a detector arrangement (10) arranged separate from the rotary arm (2; 102; 202; 302; 402; 502) for detecting a radiation beam spot, the radiation beam spot (40; 140; 240; 340; 440; 540) having an angular disposition; a first reflective surface (4; 104; 204; 304; 404; 504) attached to the rotary arm (2; 102; 202; 302; 402; 502); a second reflective surface (6; 106; 206; 306; 406; 506) attached to the rotary arm (2; 102; 302; 402; 502); a first light path (LP 1; LP 1 O 1; LP201; LP301; LP401; LP501) running from a location on the record carrier to said first reflective surface; a second light path (LP2; LP102; LP202; LP302; LP402; LP502) running from said first reflective surface to said second reflective surface; a third light path (LP3; LP103