摘要:
In the described method of producing a plurality of bodies bearing equal imprints of a stamp as optical structures, a stamp (13) is initially produced, by attaching particles (14) to a surface (15) of an auxiliary body (16); than, the stamp (13) is used to produce an imprint (11) on a plurality of bodies (10). Optical structures can be irradiated, producing on a screen a speckle pattern indicative of a key. It is substantially impossible to clone a given optical structure with current technological means. Optical structures represent physical One-Way Functions, easy to compute in the forward sense but unfeasible to reverse. Thus, they can be used to build an access/copy protection system of user information contained in an information carrier associated with the body 10. The reproducibility of the optical structures makes this method suitable for optical disks.
摘要:
A lens driving device (1) or an optical read and/or write system comprises a mechanical structure (3) with an objective lens (2) and an actuator (4, 4′, 6) for controlling the lens position. The lens driving device comprises a further actuator (5, 5a, 5b, 5′) on or near the mechanical structure so as to at least partially compensate motion generated by the first-mentioned actuator (4,6).
摘要:
In short the invention may be described as follows: An optical pick-up actuator (1) has a lens holder (2). The lens holder has tracking (5r) and focusing (5f) coils which substantially extend in two parallel planes at a side of the lens holder (2). A magnet system (7) is arranged separately from the lens holder and extends beyond said planes, said magnet system cooperating with the tracking and focusing coils, the coil systems being arranged for effecting tilt through cooperation with the magnet system. Preferably, a coil system is provided at each of two opposite sides of the lens holder.
摘要:
The invention provides a method and apparatus 1, for determining the quality of the optical disk read signal. Said method comprises: comparing said optical disk read signal with a preset reference signal to acquire the signal values correlated with said preset reference signal in said optical disk read signal, with said correlated signal values satisfying a preset condition; sampling said optical disk read signal to acquire a, plurality of sampled signal values; acquiring, with respect to each of said signal values, two sampled signal values that are adjacent to each of said signal values according to said signal values and said sampled signal values; and finally determining the quality of said optical disk read signal on the basis of the preset relationship between the average and the maximum values of the differences of said two adjacent sampled signal values that are corresponding to each of the signal values.
摘要:
The invention relates to an optical device comprising; a) a polymer film (101) comprising a first surface (107) and a second surface (108), b) a first electrode (102) mapped on said first surface (107), c) a second electrode (103) mapped on said second surface (108), d) a deformable optical element (104) mapped on said first electrode (102) or on said first surface (107).
摘要:
A method is described for discriminating different types of disc defects in an optical disc drive apparatus (1) of a type comprising: scanning means (30) for scanning a record track of an optical disc (2) and for generating a read signal (SR), the scanning means (30) comprising at least one displaceable read/write element (34); actuator means (50) for controlling the positioning of said read/write element; a control circuit (90) for generating at least one actuator control signal (SCR, SCF, SCT) on the basis of at least one signal component (REN, FEN) of said read signal, the control circuit having a plurality of predetermined controller settings; the method comprising the steps of: deriving from said read signal at least one signal component (MIRN ; performing a frequency analysis of said signal component; selectively setting one of said plurality of predetermined controller settings on the basis of the results of said frequency analysis.
摘要:
An optical disk drive (50) comprises a radial servo system (70) for driving the position of an optical head (52) for scanning an optical disk (10) comprising at least one recording track (11; 12, 13), a focus servo system (80) for controlling the focussing of an optical beam, and a data retrieval system (90) for regenerating the digital data recorded on disk. Operative parameters of the radial servo system (70) and/or focus servo system (80) and/or data retrieval system (90) are frozen or are set to predetermined values as soon as the optical head (52) reaches a predetermined location (17) along a current track (12; 13) which is determined on the basis of a defect entry location (17) along a previous track (11; 12).
摘要:
The present invention relates to a method for improving the robustness of the readout from an optical disk in an optical disk drive, such as an optical disk of the following format: compact disk (CD), digital versatile/video disk (DVD) and Blu Ray disk (BD). The invention provides a way of obtaining an optimized radial tracking error signal using an open loop, i.e. with no feedback, in order to improve a subsequent closed loop control mechanism, preferably involving the radial tracking error signal. During the optimization of the open loop radial tracking error signal one ore more drive parameters of the optical disk drive is varied. It is a particular advantage of the invention that an improved optical read-out may be obtained if the optical disk has one or more parameters outside the specifications and/or standards associated with the optical disk. The present invention also relates to an apparatus for using the method, i.e. an optical disk drive.
摘要:
A controller (30) is capable of operating in two possible operative modes, each mode having a corresponding characteristic (11; 12). Said characteristics have an overlap in a range of error signal values [TLL-TN]. The controller is capable of switching from one mode to another, based on the value of the time-derivative (( ) of the input error signal (e), so that, for a certain input error signal within said range [TLL-TN], the controller can be in any of its modes.
摘要:
An apparatus for scanning a track on a record carrier has a head (22) and front end circuitry (31) for scanning the track and generating scanning signals. A detection unit (32) detects anomalies in the scanning signal, for example for adjusting a tracking servo. The detection unit (32) calculates a mean value of the scanning signal and compares the mean value to a threshold for providing an anomaly detection signal (33). Further a classification unit (34) provides an indication of the type of defect for determining a suitable responsive or corrective action.