Abstract: A method for triggering a resonant charging circuit for a device for generating short-wavelength radiation based on discharge plasma is described. Switching times of the resonant charging circuit are determined in a non-time-critical method segment by simulation and are stored to be repeatedly retrievable. Measurement values of the resonant charging circuit are determined in real time in a time-critical method segment. At least one second switching time (t2) at which a discharging switch of the resonant charging circuit is triggered in order to supply at a firing time (t3) a discharge voltage (Uwanted), and the firing time (t3) are calculated. The device has a first input unit, a first simulation unit, a first regression unit, a first measurement value unit, a first evaluation unit and a control unit for triggering a discharging switch of the resonant charging circuit.

Abstract: A method for controlling a discharge plasma-based radiation source for stabilizing a radiation dose emitted in a pulsed manner is disclosed. A calibration function is determined from a relationship between values of an input quantity and values of an operating parameter of the source by applying different values of the input quantity to the source. Reference value selected from the values of the operating parameter is brought about during a pulse of the source. The value of a test quantity is acquired at each pulse. Any quantity influencing the emitted radiation dose can be selected as test quantity. A statistical value is formed from a defined quantity of values of the test quantity. A deviation between the statistical value and the reference value is determined. A result of a comparison of the deviation with a predefined tolerance range determines whether the method is repeated.

Abstract: A method for triggering a resonant charging circuit for a device for generating short-wavelength radiation based on discharge plasma is described. Switching times of the resonant charging circuit are determined in a non-time-critical method segment by simulation and are stored to be repeatedly retrievable. Measurement values of the resonant charging circuit are determined in real time in a time-critical method segment. At least one second switching time (t2) at which a discharging switch of the resonant charging circuit is triggered in order to supply at a firing time (t3) a discharge voltage (Uwanted), and the firing time (t3) are calculated. The device has a first input unit, a first simulation unit, a first regression unit, a first measurement value unit, a first evaluation unit and a control unit for triggering a discharging switch of the resonant charging circuit.

Abstract: A method for controlling a discharge plasma-based radiation source for stabilizing a radiation dose emitted in a pulsed manner is disclosed. A calibration function is determined from a relationship between values of an input quantity and values of an operating parameter of the source by applying different values of the input quantity to the source. Reference value selected from the values of the operating parameter is brought about during a pulse of the source. The value of a test quantity is acquired at each pulse. Any quantity influencing the emitted radiation dose can be selected as test quantity. A statistical value is formed from a defined quantity of values of the test quantity. A deviation between the statistical value and the reference value is determined. A result of a comparison of the deviation with a predefined tolerance range determines whether the method is repeated.

Abstract: A method of determining a disk type of an optical disk is provided to comprise steps of: using a first light path for forming an incident beam; moving an objective lens system corresponding to the first light path from a start position towards the optical disk; receiving a sensor output signal during the movement of the objective lens system, wherein the sensor output signal includes a central aperture signal; determining the disk type of the optical disk according to the central aperture signal.

Abstract: The present invention relates to a method for operating an optical drive system capable of reproducing/recording information from/to an optical carrier (30), wherein a position error and a speed error of a radiation spot (12, 53) on the carrier has been created due to an unreliable error signal which has been generated due to a surface defect (52). The method includes the steps of registering values of e.g. servo signals, determining the occurrence of a defect using a defect detector DEFO (22), generating a first and a second compensation signal and applying these compensation signals to the control system (10) of the optical drive system. The first compensation signal is capable of reducing the speed error and the second compensation signal is capable of reducing the position error. Thus, the application of the compensation signals immediately after the unreliable error signals reduces the position error and the speed error of the focussed radiation spot (12, 53).

Abstract: An optical disk drive for determining a disk type associated with a substrate thickness of an optical disk comprising a substrate is provided to comprise a source to generate a beam, an optical arrangement arranged to direct the beam to the optical disk for forming an incident beam, a sensor arranged to sense a reflected beam and to produce a sensor output signal, a focus system comprising an objective lens system and a focus controller, wherein the objective lens system is arranged to focus the incident beam into a spot, and the focus controller is arranged to generate a focus control signal to drive and position the objective lens system; and a controller arranged to cooperate with the focus controller for moving the objective lens system, to receive the central aperture signal during the movement of the objective lens system, to analyze the central aperture signal for determining the focus actuator position, and to determine the disk type associated with the substrate thickness.

Abstract: The present invention discloses an optical apparatus capable of reproducing/recording information from/to an optical carrier, e.g. a DVD or BD disk. The apparatus has control means for positioning/focusing a radiation beam (5) on the carrier and photo detection means for detection of radiation reflected from the carrier. Additionally, defect detection means (DEFO) for detection of surface defect areas (A1, A2) can indicate where surface defects, e.g. scratches etc., are present. Processing means are adapted for integrating, and preferably differentiate, error signals (RE, FE) immediately after the beam (5.b) is exiting a defect area (A1) for generating adaptive control signals (AD_RE, AD_FE). The optical system is adapted to apply the adaptive control signals (AD_RE, AD_FE) when the beam is positioned in the defect area (A1) again, thereby reducing off-track deviation as the beam (5.d) exits the defect area (A1).

Abstract: The present invention relates to a method for operating an optical drive system capable of reproducing/recording information from/to an optical carrier (30), wherein a position error and a speed error of a radiation spot (12, 53) on the carrier has been created due to an unreliable error signal which has been generated due to a surface defect (52). The method includes the steps of registering values of e.g. servo signals, determining the occurrence of a defect using a defect detector DEFO (22), generating a first and a second compensation signal and applying these compensation signals to the control system (10) of the optical drive system. The first compensation signal is capable of reducing the speed error and the second compensation signal is capable of reducing the position error. Thus, the application of the compensation signals immediately after the unreliable error signals reduces the position error and the speed error of the focussed radiation spot (12, 53).