Optical scanning device

摘要

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 ; LP 201 ; LP 301 ; LP 401 ; LP 501 ) running from a location on the record carrier to said first reflective surface; a second light path (LP 2 ; LP 102 ; LP 202 ; LP 302 ; LP 402 ; LP 502 ) running from said first reflective surface to said second reflective surface; a third light path (LP 3 ; LP 103 ; LP 203 ; LP 303 ; LP 403 ; LP 503 ) running from said second reflective surface to said detector arrangement ( 10 ). The rotary arm includes at least one optical inversion element ( 52; 54; 56; 58; 64; 66 ) arranged such that a dependence between variation of the angular disposition of the radiation beam spot and variation of the angular position of the rotary arm is reduced.