Abstract: A miniaturised optical pickup head for an optical storage system in which a well-collimated beam is generated. The optical pickup head comprises an optical system comprising a collimator leans and a reflective or diffractive elements, such as a 45 degree mirror. The optical system is attached to a cover plate and extends into a cavity defined by the cover plate and a substrate on which a radiation source is provided. The cover plate, and therefore, the optical system including the collimator lens is movable relative to the radiation source in a direction parallel to the optical axis of the collimator lends and the substrate so as to adjust the alignment of the collimator lens relative to the radiation beam generated by the radiation source.

Abstract: The invention relates to an optical scanning device and to an optical wavefront modifier for use therein, for scanning an optical record carrier, such as an optical disk comprising an information layer. The device comprises a radiation source (9) for emitting an incident radiation beam; a detection system comprising an information signal detector (25) arranged to receive radiation reflected from the information layer and to detect an information signal therein; an optical system (14, 12) for focusing the incident radiation beam to a spot on in the record carrier, and for directing the reflected radiation beam onto the information signal detector; and an optical wavefront modifier (10) arranged in the path of the incident radiation beam and the reflected radiation beam.

Abstract: A system and method is provided which compensates for the effects of relaxation oscillations and turn-on delays of diode laser devices. In particular, there is provided a method and system for tuning the shape of the power profile of an output optical signal and its position with respect to a channel bit clock of an optical recording system.

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: The invention relates to an optical disk drive, which can be built very small. In order to solve cooling problems and collecting light reflected from the disk with maximum efficiency an optical disk drive is proposed comprising:—a laser diode for generating a laser beam, said laser diode being located at a fixed position in the drive,—an objective for focussing said laser beam on an optical disk,—a light guide for guiding said laser beam from said laser diode to said objective,—a detector for detecting light reflected from the optical disk, and—a movable swing arm for carrying said objective and said detector, said detector being arranged close to said objective such that the light reflected from the optical disk through said objective is detected.

Abstract: An optical scanning device (1) for scanning an information layer (4) of an optical record carrier (2), the device (1) comprising a radiation source (11) for generating a radiation beam (12, 15, 20) and an objective system (18) for converging the radiation beam on the information layer, the information layer being covered by a transparent layer (3) of thickness td and refractive index nd. The objective system comprises a lens having a protection device projecting away from the lens towards the optical record carrier such that the distance between the protection device and the optical record carrier is less than the free working distance. The lens satisfies the condition: where D is the entrance pupil diameter, FWD is the free working distance, and D, FWD, t and td are all expressed in millimeters and where FWD+td/nd<0.51.

Abstract: An optical head for scanning a dual-layer disk includes a polarising beam splitter for splitting an input beam (7) from a single radiation source to form two separate, orthogonally polarised beams (9, 10). One of the beams is passed trough a fixed collimator lens (13), whilst the other is passed trough a movable collimator lens (21). The beams are directed along a common beam path through a common objective lens (17) which is itself movably mounted. Focusing and terror correction is provided separately for each layer when scanning the two layers by actuation of the objective (17) and movable collimator (21), respectively. The use of a single radiation source and a single objective provides a reduction in the number of components, and the complexity of components, required to read a dual-layer disk.

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